(function(global) {
// CodeMirror version 3.15
//
// CodeMirror is the only global var we claim
    var CodeMirror = (function() {
        "use strict";

        // BROWSER SNIFFING

        // Crude, but necessary to handle a number of hard-to-feature-detect
        // bugs and behavior differences.
        var gecko = /gecko\/\d/i.test(navigator.userAgent);
        var ie = /MSIE \d/.test(navigator.userAgent);
        var ie_lt8 = ie && (document.documentMode == null || document.documentMode < 8);
        var ie_lt9 = ie && (document.documentMode == null || document.documentMode < 9);
        var webkit = /WebKit\//.test(navigator.userAgent);
        var qtwebkit = webkit && /Qt\/\d+\.\d+/.test(navigator.userAgent);
        var chrome = /Chrome\//.test(navigator.userAgent);
        var opera = /Opera\//.test(navigator.userAgent);
        var safari = /Apple Computer/.test(navigator.vendor);
        var khtml = /KHTML\//.test(navigator.userAgent);
        var mac_geLion = /Mac OS X 1\d\D([7-9]|\d\d)\D/.test(navigator.userAgent);
        var mac_geMountainLion = /Mac OS X 1\d\D([8-9]|\d\d)\D/.test(navigator.userAgent);
        var phantom = /PhantomJS/.test(navigator.userAgent);

        var ios = /AppleWebKit/.test(navigator.userAgent) && /Mobile\/\w+/.test(navigator.userAgent);
        // This is woefully incomplete. Suggestions for alternative methods welcome.
        var mobile = ios || /Android|webOS|BlackBerry|Opera Mini|Opera Mobi|IEMobile/i.test(navigator.userAgent);
        var mac = ios || /Mac/.test(navigator.platform);
        var windows = /windows/i.test(navigator.platform);

        var opera_version = opera && navigator.userAgent.match(/Version\/(\d*\.\d*)/);
        if (opera_version) opera_version = Number(opera_version[1]);
        if (opera_version && opera_version >= 15) { opera = false; webkit = true; }
        // Some browsers use the wrong event properties to signal cmd/ctrl on OS X
        var flipCtrlCmd = mac && (qtwebkit || opera && (opera_version == null || opera_version < 12.11));
        var captureMiddleClick = gecko || (ie && !ie_lt9);

        // Optimize some code when these features are not used
        var sawReadOnlySpans = false, sawCollapsedSpans = false;

        // CONSTRUCTOR

        function CodeMirror(place, options) {
            if (!(this instanceof CodeMirror)) return new CodeMirror(place, options);

            this.options = options = options || {};
            // Determine effective options based on given values and defaults.
            for (var opt in defaults) if (!options.hasOwnProperty(opt) && defaults.hasOwnProperty(opt))
                options[opt] = defaults[opt];
            setGuttersForLineNumbers(options);

            var docStart = typeof options.value == "string" ? 0 : options.value.first;
            var display = this.display = makeDisplay(place, docStart);
            display.wrapper.CodeMirror = this;
            updateGutters(this);
            if (options.autofocus && !mobile) focusInput(this);

            this.state = {keyMaps: [],
                overlays: [],
                modeGen: 0,
                overwrite: false, focused: false,
                suppressEdits: false, pasteIncoming: false,
                draggingText: false,
                highlight: new Delayed()};

            themeChanged(this);
            if (options.lineWrapping)
                this.display.wrapper.className += " CodeMirror-wrap";

            var doc = options.value;
            if (typeof doc == "string") doc = new Doc(options.value, options.mode);
            operation(this, attachDoc)(this, doc);

            // Override magic textarea content restore that IE sometimes does
            // on our hidden textarea on reload
            if (ie) setTimeout(bind(resetInput, this, true), 20);

            registerEventHandlers(this);
            // IE throws unspecified error in certain cases, when
            // trying to access activeElement before onload
            var hasFocus; try { hasFocus = (document.activeElement == display.input); } catch(e) { }
            if (hasFocus || (options.autofocus && !mobile)) setTimeout(bind(onFocus, this), 20);
            else onBlur(this);

            operation(this, function() {
                for (var opt in optionHandlers)
                    if (optionHandlers.propertyIsEnumerable(opt))
                        optionHandlers[opt](this, options[opt], Init);
                for (var i = 0; i < initHooks.length; ++i) initHooks[i](this);
            })();
        }

        // DISPLAY CONSTRUCTOR

        function makeDisplay(place, docStart) {
            var d = {};

            var input = d.input = elt("textarea", null, null, "position: absolute; padding: 0; width: 1px; height: 1em; outline: none; font-size: 4px;");
            if (webkit) input.style.width = "1000px";
            else input.setAttribute("wrap", "off");
            // if border: 0; -- iOS fails to open keyboard (issue #1287)
            if (ios) input.style.border = "1px solid black";
            input.setAttribute("autocorrect", "off"); input.setAttribute("autocapitalize", "off"); input.setAttribute("spellcheck", "false");

            // Wraps and hides input textarea
            d.inputDiv = elt("div", [input], null, "overflow: hidden; position: relative; width: 3px; height: 0px;");
            // The actual fake scrollbars.
            d.scrollbarH = elt("div", [elt("div", null, null, "height: 1px")], "CodeMirror-hscrollbar");
            d.scrollbarV = elt("div", [elt("div", null, null, "width: 1px")], "CodeMirror-vscrollbar");
            d.scrollbarFiller = elt("div", null, "CodeMirror-scrollbar-filler");
            d.gutterFiller = elt("div", null, "CodeMirror-gutter-filler");
            // DIVs containing the selection and the actual code
            d.lineDiv = elt("div", null, "CodeMirror-code");
            d.selectionDiv = elt("div", null, null, "position: relative; z-index: 1");
            // Blinky cursor, and element used to ensure cursor fits at the end of a line
            d.cursor = elt("div", "\u00a0", "CodeMirror-cursor");
            // Secondary cursor, shown when on a 'jump' in bi-directional text
            d.otherCursor = elt("div", "\u00a0", "CodeMirror-cursor CodeMirror-secondarycursor");
            // Used to measure text size
            d.measure = elt("div", null, "CodeMirror-measure");
            // Wraps everything that needs to exist inside the vertically-padded coordinate system
            d.lineSpace = elt("div", [d.measure, d.selectionDiv, d.lineDiv, d.cursor, d.otherCursor],
                null, "position: relative; outline: none");
            // Moved around its parent to cover visible view
            d.mover = elt("div", [elt("div", [d.lineSpace], "CodeMirror-lines")], null, "position: relative");
            // Set to the height of the text, causes scrolling
            d.sizer = elt("div", [d.mover], "CodeMirror-sizer");
            // D is needed because behavior of elts with overflow: auto and padding is inconsistent across browsers
            d.heightForcer = elt("div", null, null, "position: absolute; height: " + scrollerCutOff + "px; width: 1px;");
            // Will contain the gutters, if any
            d.gutters = elt("div", null, "CodeMirror-gutters");
            d.lineGutter = null;
            // Provides scrolling
            d.scroller = elt("div", [d.sizer, d.heightForcer, d.gutters], "CodeMirror-scroll");
            d.scroller.setAttribute("tabIndex", "-1");
            // The element in which the editor lives.
            d.wrapper = elt("div", [d.inputDiv, d.scrollbarH, d.scrollbarV,
                d.scrollbarFiller, d.gutterFiller, d.scroller], "CodeMirror");
            // Work around IE7 z-index bug
            if (ie_lt8) { d.gutters.style.zIndex = -1; d.scroller.style.paddingRight = 0; }
            if (place.appendChild) place.appendChild(d.wrapper); else place(d.wrapper);

            // Needed to hide big blue blinking cursor on Mobile Safari
            if (ios) input.style.width = "0px";
            if (!webkit) d.scroller.draggable = true;
            // Needed to handle Tab key in KHTML
            if (khtml) { d.inputDiv.style.height = "1px"; d.inputDiv.style.position = "absolute"; }
            // Need to set a minimum width to see the scrollbar on IE7 (but must not set it on IE8).
            else if (ie_lt8) d.scrollbarH.style.minWidth = d.scrollbarV.style.minWidth = "18px";

            // Current visible range (may be bigger than the view window).
            d.viewOffset = d.lastSizeC = 0;
            d.showingFrom = d.showingTo = docStart;

            // Used to only resize the line number gutter when necessary (when
            // the amount of lines crosses a boundary that makes its width change)
            d.lineNumWidth = d.lineNumInnerWidth = d.lineNumChars = null;
            // See readInput and resetInput
            d.prevInput = "";
            // Set to true when a non-horizontal-scrolling widget is added. As
            // an optimization, widget aligning is skipped when d is false.
            d.alignWidgets = false;
            // Flag that indicates whether we currently expect input to appear
            // (after some event like 'keypress' or 'input') and are polling
            // intensively.
            d.pollingFast = false;
            // Self-resetting timeout for the poller
            d.poll = new Delayed();

            d.cachedCharWidth = d.cachedTextHeight = null;
            d.measureLineCache = [];
            d.measureLineCachePos = 0;

            // Tracks when resetInput has punted to just putting a short
            // string instead of the (large) selection.
            d.inaccurateSelection = false;

            // Tracks the maximum line length so that the horizontal scrollbar
            // can be kept static when scrolling.
            d.maxLine = null;
            d.maxLineLength = 0;
            d.maxLineChanged = false;

            // Used for measuring wheel scrolling granularity
            d.wheelDX = d.wheelDY = d.wheelStartX = d.wheelStartY = null;

            return d;
        }

        // STATE UPDATES

        // Used to get the editor into a consistent state again when options change.

        function loadMode(cm) {
            cm.doc.mode = CodeMirror.getMode(cm.options, cm.doc.modeOption);
            cm.doc.iter(function(line) {
                if (line.stateAfter) line.stateAfter = null;
                if (line.styles) line.styles = null;
            });
            cm.doc.frontier = cm.doc.first;
            startWorker(cm, 100);
            cm.state.modeGen++;
            if (cm.curOp) regChange(cm);
        }

        function wrappingChanged(cm) {
            if (cm.options.lineWrapping) {
                cm.display.wrapper.className += " CodeMirror-wrap";
                cm.display.sizer.style.minWidth = "";
            } else {
                cm.display.wrapper.className = cm.display.wrapper.className.replace(" CodeMirror-wrap", "");
                computeMaxLength(cm);
            }
            estimateLineHeights(cm);
            regChange(cm);
            clearCaches(cm);
            setTimeout(function(){updateScrollbars(cm);}, 100);
        }

        function estimateHeight(cm) {
            var th = textHeight(cm.display), wrapping = cm.options.lineWrapping;
            var perLine = wrapping && Math.max(5, cm.display.scroller.clientWidth / charWidth(cm.display) - 3);
            return function(line) {
                if (lineIsHidden(cm.doc, line))
                    return 0;
                else if (wrapping)
                    return (Math.ceil(line.text.length / perLine) || 1) * th;
                else
                    return th;
            };
        }

        function estimateLineHeights(cm) {
            var doc = cm.doc, est = estimateHeight(cm);
            doc.iter(function(line) {
                var estHeight = est(line);
                if (estHeight != line.height) updateLineHeight(line, estHeight);
            });
        }

        function keyMapChanged(cm) {
            var map = keyMap[cm.options.keyMap], style = map.style;
            cm.display.wrapper.className = cm.display.wrapper.className.replace(/\s*cm-keymap-\S+/g, "") +
                (style ? " cm-keymap-" + style : "");
            cm.state.disableInput = map.disableInput;
        }

        function themeChanged(cm) {
            cm.display.wrapper.className = cm.display.wrapper.className.replace(/\s*cm-s-\S+/g, "") +
                cm.options.theme.replace(/(^|\s)\s*/g, " cm-s-");
            clearCaches(cm);
        }

        function guttersChanged(cm) {
            updateGutters(cm);
            regChange(cm);
            setTimeout(function(){alignHorizontally(cm);}, 20);
        }

        function updateGutters(cm) {
            var gutters = cm.display.gutters, specs = cm.options.gutters;
            removeChildren(gutters);
            for (var i = 0; i < specs.length; ++i) {
                var gutterClass = specs[i];
                var gElt = gutters.appendChild(elt("div", null, "CodeMirror-gutter " + gutterClass));
                if (gutterClass == "CodeMirror-linenumbers") {
                    cm.display.lineGutter = gElt;
                    gElt.style.width = (cm.display.lineNumWidth || 1) + "px";
                }
            }
            gutters.style.display = i ? "" : "none";
        }

        function lineLength(doc, line) {
            if (line.height == 0) return 0;
            var len = line.text.length, merged, cur = line;
            while (merged = collapsedSpanAtStart(cur)) {
                var found = merged.find();
                cur = getLine(doc, found.from.line);
                len += found.from.ch - found.to.ch;
            }
            cur = line;
            while (merged = collapsedSpanAtEnd(cur)) {
                var found = merged.find();
                len -= cur.text.length - found.from.ch;
                cur = getLine(doc, found.to.line);
                len += cur.text.length - found.to.ch;
            }
            return len;
        }

        function computeMaxLength(cm) {
            var d = cm.display, doc = cm.doc;
            d.maxLine = getLine(doc, doc.first);
            d.maxLineLength = lineLength(doc, d.maxLine);
            d.maxLineChanged = true;
            doc.iter(function(line) {
                var len = lineLength(doc, line);
                if (len > d.maxLineLength) {
                    d.maxLineLength = len;
                    d.maxLine = line;
                }
            });
        }

        // Make sure the gutters options contains the element
        // "CodeMirror-linenumbers" when the lineNumbers option is true.
        function setGuttersForLineNumbers(options) {
            var found = false;
            for (var i = 0; i < options.gutters.length; ++i) {
                if (options.gutters[i] == "CodeMirror-linenumbers") {
                    if (options.lineNumbers) found = true;
                    else options.gutters.splice(i--, 1);
                }
            }
            if (!found && options.lineNumbers)
                options.gutters.push("CodeMirror-linenumbers");
        }

        // SCROLLBARS

        // Re-synchronize the fake scrollbars with the actual size of the
        // content. Optionally force a scrollTop.
        function updateScrollbars(cm) {
            var d = cm.display, docHeight = cm.doc.height;
            var totalHeight = docHeight + paddingVert(d);
            d.sizer.style.minHeight = d.heightForcer.style.top = totalHeight + "px";
            d.gutters.style.height = Math.max(totalHeight, d.scroller.clientHeight - scrollerCutOff) + "px";
            var scrollHeight = Math.max(totalHeight, d.scroller.scrollHeight);
            var needsH = d.scroller.scrollWidth > (d.scroller.clientWidth + 1);
            var needsV = scrollHeight > (d.scroller.clientHeight + 1);
            if (needsV) {
                d.scrollbarV.style.display = "block";
                d.scrollbarV.style.bottom = needsH ? scrollbarWidth(d.measure) + "px" : "0";
                d.scrollbarV.firstChild.style.height =
                    (scrollHeight - d.scroller.clientHeight + d.scrollbarV.clientHeight) + "px";
            } else d.scrollbarV.style.display = "";
            if (needsH) {
                d.scrollbarH.style.display = "block";
                d.scrollbarH.style.right = needsV ? scrollbarWidth(d.measure) + "px" : "0";
                d.scrollbarH.firstChild.style.width =
                    (d.scroller.scrollWidth - d.scroller.clientWidth + d.scrollbarH.clientWidth) + "px";
            } else d.scrollbarH.style.display = "";
            if (needsH && needsV) {
                d.scrollbarFiller.style.display = "block";
                d.scrollbarFiller.style.height = d.scrollbarFiller.style.width = scrollbarWidth(d.measure) + "px";
            } else d.scrollbarFiller.style.display = "";
            if (needsH && cm.options.coverGutterNextToScrollbar && cm.options.fixedGutter) {
                d.gutterFiller.style.display = "block";
                d.gutterFiller.style.height = scrollbarWidth(d.measure) + "px";
                d.gutterFiller.style.width = d.gutters.offsetWidth + "px";
            } else d.gutterFiller.style.display = "";

            if (mac_geLion && scrollbarWidth(d.measure) === 0)
                d.scrollbarV.style.minWidth = d.scrollbarH.style.minHeight = mac_geMountainLion ? "18px" : "12px";
        }

        function visibleLines(display, doc, viewPort) {
            var top = display.scroller.scrollTop, height = display.wrapper.clientHeight;
            if (typeof viewPort == "number") top = viewPort;
            else if (viewPort) {top = viewPort.top; height = viewPort.bottom - viewPort.top;}
            top = Math.floor(top - paddingTop(display));
            var bottom = Math.ceil(top + height);
            return {from: lineAtHeight(doc, top), to: lineAtHeight(doc, bottom)};
        }

        // LINE NUMBERS

        function alignHorizontally(cm) {
            var display = cm.display;
            if (!display.alignWidgets && (!display.gutters.firstChild || !cm.options.fixedGutter)) return;
            var comp = compensateForHScroll(display) - display.scroller.scrollLeft + cm.doc.scrollLeft;
            var gutterW = display.gutters.offsetWidth, l = comp + "px";
            for (var n = display.lineDiv.firstChild; n; n = n.nextSibling) if (n.alignable) {
                for (var i = 0, a = n.alignable; i < a.length; ++i) a[i].style.left = l;
            }
            if (cm.options.fixedGutter)
                display.gutters.style.left = (comp + gutterW) + "px";
        }

        function maybeUpdateLineNumberWidth(cm) {
            if (!cm.options.lineNumbers) return false;
            var doc = cm.doc, last = lineNumberFor(cm.options, doc.first + doc.size - 1), display = cm.display;
            if (last.length != display.lineNumChars) {
                var test = display.measure.appendChild(elt("div", [elt("div", last)],
                    "CodeMirror-linenumber CodeMirror-gutter-elt"));
                var innerW = test.firstChild.offsetWidth, padding = test.offsetWidth - innerW;
                display.lineGutter.style.width = "";
                display.lineNumInnerWidth = Math.max(innerW, display.lineGutter.offsetWidth - padding);
                display.lineNumWidth = display.lineNumInnerWidth + padding;
                display.lineNumChars = display.lineNumInnerWidth ? last.length : -1;
                display.lineGutter.style.width = display.lineNumWidth + "px";
                return true;
            }
            return false;
        }

        function lineNumberFor(options, i) {
            return String(options.lineNumberFormatter(i + options.firstLineNumber));
        }
        function compensateForHScroll(display) {
            return getRect(display.scroller).left - getRect(display.sizer).left;
        }

        // DISPLAY DRAWING

        function updateDisplay(cm, changes, viewPort, forced) {
            var oldFrom = cm.display.showingFrom, oldTo = cm.display.showingTo, updated;
            var visible = visibleLines(cm.display, cm.doc, viewPort);
            for (;;) {
                if (!updateDisplayInner(cm, changes, visible, forced)) break;
                forced = false;
                updated = true;
                updateSelection(cm);
                updateScrollbars(cm);

                // Clip forced viewport to actual scrollable area
                if (viewPort)
                    viewPort = Math.min(cm.display.scroller.scrollHeight - cm.display.scroller.clientHeight,
                            typeof viewPort == "number" ? viewPort : viewPort.top);
                visible = visibleLines(cm.display, cm.doc, viewPort);
                if (visible.from >= cm.display.showingFrom && visible.to <= cm.display.showingTo)
                    break;
                changes = [];
            }

            if (updated) {
                signalLater(cm, "update", cm);
                if (cm.display.showingFrom != oldFrom || cm.display.showingTo != oldTo)
                    signalLater(cm, "viewportChange", cm, cm.display.showingFrom, cm.display.showingTo);
            }
            return updated;
        }

        // Uses a set of changes plus the current scroll position to
        // determine which DOM updates have to be made, and makes the
        // updates.
        function updateDisplayInner(cm, changes, visible, forced) {
            var display = cm.display, doc = cm.doc;
            if (!display.wrapper.clientWidth) {
                display.showingFrom = display.showingTo = doc.first;
                display.viewOffset = 0;
                return;
            }

            // Bail out if the visible area is already rendered and nothing changed.
            if (!forced && changes.length == 0 &&
                visible.from > display.showingFrom && visible.to < display.showingTo)
                return;

            if (maybeUpdateLineNumberWidth(cm))
                changes = [{from: doc.first, to: doc.first + doc.size}];
            var gutterW = display.sizer.style.marginLeft = display.gutters.offsetWidth + "px";
            display.scrollbarH.style.left = cm.options.fixedGutter ? gutterW : "0";

            // Used to determine which lines need their line numbers updated
            var positionsChangedFrom = Infinity;
            if (cm.options.lineNumbers)
                for (var i = 0; i < changes.length; ++i)
                    if (changes[i].diff) { positionsChangedFrom = changes[i].from; break; }

            var end = doc.first + doc.size;
            var from = Math.max(visible.from - cm.options.viewportMargin, doc.first);
            var to = Math.min(end, visible.to + cm.options.viewportMargin);
            if (display.showingFrom < from && from - display.showingFrom < 20) from = Math.max(doc.first, display.showingFrom);
            if (display.showingTo > to && display.showingTo - to < 20) to = Math.min(end, display.showingTo);
            if (sawCollapsedSpans) {
                from = lineNo(visualLine(doc, getLine(doc, from)));
                while (to < end && lineIsHidden(doc, getLine(doc, to))) ++to;
            }

            // Create a range of theoretically intact lines, and punch holes
            // in that using the change info.
            var intact = [{from: Math.max(display.showingFrom, doc.first),
                to: Math.min(display.showingTo, end)}];
            if (intact[0].from >= intact[0].to) intact = [];
            else intact = computeIntact(intact, changes);
            // When merged lines are present, we might have to reduce the
            // intact ranges because changes in continued fragments of the
            // intact lines do require the lines to be redrawn.
            if (sawCollapsedSpans)
                for (var i = 0; i < intact.length; ++i) {
                    var range = intact[i], merged;
                    while (merged = collapsedSpanAtEnd(getLine(doc, range.to - 1))) {
                        var newTo = merged.find().from.line;
                        if (newTo > range.from) range.to = newTo;
                        else { intact.splice(i--, 1); break; }
                    }
                }

            // Clip off the parts that won't be visible
            var intactLines = 0;
            for (var i = 0; i < intact.length; ++i) {
                var range = intact[i];
                if (range.from < from) range.from = from;
                if (range.to > to) range.to = to;
                if (range.from >= range.to) intact.splice(i--, 1);
                else intactLines += range.to - range.from;
            }
            if (!forced && intactLines == to - from && from == display.showingFrom && to == display.showingTo) {
                updateViewOffset(cm);
                return;
            }
            intact.sort(function(a, b) {return a.from - b.from;});

            // Avoid crashing on IE's "unspecified error" when in iframes
            try {
                var focused = document.activeElement;
            } catch(e) {}
            if (intactLines < (to - from) * .7) display.lineDiv.style.display = "none";
            patchDisplay(cm, from, to, intact, positionsChangedFrom);
            display.lineDiv.style.display = "";
            if (focused && document.activeElement != focused && focused.offsetHeight) focused.focus();

            var different = from != display.showingFrom || to != display.showingTo ||
                display.lastSizeC != display.wrapper.clientHeight;
            // This is just a bogus formula that detects when the editor is
            // resized or the font size changes.
            if (different) {
                display.lastSizeC = display.wrapper.clientHeight;
                startWorker(cm, 400);
            }
            display.showingFrom = from; display.showingTo = to;

            updateHeightsInViewport(cm);
            updateViewOffset(cm);

            return true;
        }

        function updateHeightsInViewport(cm) {
            var display = cm.display;
            var prevBottom = display.lineDiv.offsetTop;
            for (var node = display.lineDiv.firstChild, height; node; node = node.nextSibling) if (node.lineObj) {
                if (ie_lt8) {
                    var bot = node.offsetTop + node.offsetHeight;
                    height = bot - prevBottom;
                    prevBottom = bot;
                } else {
                    var box = getRect(node);
                    height = box.bottom - box.top;
                }
                var diff = node.lineObj.height - height;
                if (height < 2) height = textHeight(display);
                if (diff > .001 || diff < -.001) {
                    updateLineHeight(node.lineObj, height);
                    var widgets = node.lineObj.widgets;
                    if (widgets) for (var i = 0; i < widgets.length; ++i)
                        widgets[i].height = widgets[i].node.offsetHeight;
                }
            }
        }

        function updateViewOffset(cm) {
            var off = cm.display.viewOffset = heightAtLine(cm, getLine(cm.doc, cm.display.showingFrom));
            // Position the mover div to align with the current virtual scroll position
            cm.display.mover.style.top = off + "px";
        }

        function computeIntact(intact, changes) {
            for (var i = 0, l = changes.length || 0; i < l; ++i) {
                var change = changes[i], intact2 = [], diff = change.diff || 0;
                for (var j = 0, l2 = intact.length; j < l2; ++j) {
                    var range = intact[j];
                    if (change.to <= range.from && change.diff) {
                        intact2.push({from: range.from + diff, to: range.to + diff});
                    } else if (change.to <= range.from || change.from >= range.to) {
                        intact2.push(range);
                    } else {
                        if (change.from > range.from)
                            intact2.push({from: range.from, to: change.from});
                        if (change.to < range.to)
                            intact2.push({from: change.to + diff, to: range.to + diff});
                    }
                }
                intact = intact2;
            }
            return intact;
        }

        function getDimensions(cm) {
            var d = cm.display, left = {}, width = {};
            for (var n = d.gutters.firstChild, i = 0; n; n = n.nextSibling, ++i) {
                left[cm.options.gutters[i]] = n.offsetLeft;
                width[cm.options.gutters[i]] = n.offsetWidth;
            }
            return {fixedPos: compensateForHScroll(d),
                gutterTotalWidth: d.gutters.offsetWidth,
                gutterLeft: left,
                gutterWidth: width,
                wrapperWidth: d.wrapper.clientWidth};
        }

        function patchDisplay(cm, from, to, intact, updateNumbersFrom) {
            var dims = getDimensions(cm);
            var display = cm.display, lineNumbers = cm.options.lineNumbers;
            if (!intact.length && (!webkit || !cm.display.currentWheelTarget))
                removeChildren(display.lineDiv);
            var container = display.lineDiv, cur = container.firstChild;

            function rm(node) {
                var next = node.nextSibling;
                if (webkit && mac && cm.display.currentWheelTarget == node) {
                    node.style.display = "none";
                    node.lineObj = null;
                } else {
                    node.parentNode.removeChild(node);
                }
                return next;
            }

            var nextIntact = intact.shift(), lineN = from;
            cm.doc.iter(from, to, function(line) {
                if (nextIntact && nextIntact.to == lineN) nextIntact = intact.shift();
                if (lineIsHidden(cm.doc, line)) {
                    if (line.height != 0) updateLineHeight(line, 0);
                    if (line.widgets && cur.previousSibling) for (var i = 0; i < line.widgets.length; ++i) {
                        var w = line.widgets[i];
                        if (w.showIfHidden) {
                            var prev = cur.previousSibling;
                            if (/pre/i.test(prev.nodeName)) {
                                var wrap = elt("div", null, null, "position: relative");
                                prev.parentNode.replaceChild(wrap, prev);
                                wrap.appendChild(prev);
                                prev = wrap;
                            }
                            var wnode = prev.appendChild(elt("div", [w.node], "CodeMirror-linewidget"));
                            if (!w.handleMouseEvents) wnode.ignoreEvents = true;
                            positionLineWidget(w, wnode, prev, dims);
                        }
                    }
                } else if (nextIntact && nextIntact.from <= lineN && nextIntact.to > lineN) {
                    // This line is intact. Skip to the actual node. Update its
                    // line number if needed.
                    while (cur.lineObj != line) cur = rm(cur);
                    if (lineNumbers && updateNumbersFrom <= lineN && cur.lineNumber)
                        setTextContent(cur.lineNumber, lineNumberFor(cm.options, lineN));
                    cur = cur.nextSibling;
                } else {
                    // For lines with widgets, make an attempt to find and reuse
                    // the existing element, so that widgets aren't needlessly
                    // removed and re-inserted into the dom
                    if (line.widgets) for (var j = 0, search = cur, reuse; search && j < 20; ++j, search = search.nextSibling)
                        if (search.lineObj == line && /div/i.test(search.nodeName)) { reuse = search; break; }
                    // This line needs to be generated.
                    var lineNode = buildLineElement(cm, line, lineN, dims, reuse);
                    if (lineNode != reuse) {
                        container.insertBefore(lineNode, cur);
                    } else {
                        while (cur != reuse) cur = rm(cur);
                        cur = cur.nextSibling;
                    }

                    lineNode.lineObj = line;
                }
                ++lineN;
            });
            while (cur) cur = rm(cur);
        }

        function buildLineElement(cm, line, lineNo, dims, reuse) {
            var lineElement = lineContent(cm, line);
            var markers = line.gutterMarkers, display = cm.display, wrap;

            if (!cm.options.lineNumbers && !markers && !line.bgClass && !line.wrapClass && !line.widgets)
                return lineElement;

            // Lines with gutter elements, widgets or a background class need
            // to be wrapped again, and have the extra elements added to the
            // wrapper div

            if (reuse) {
                reuse.alignable = null;
                var isOk = true, widgetsSeen = 0, insertBefore = null;
                for (var n = reuse.firstChild, next; n; n = next) {
                    next = n.nextSibling;
                    if (!/\bCodeMirror-linewidget\b/.test(n.className)) {
                        reuse.removeChild(n);
                    } else {
                        for (var i = 0; i < line.widgets.length; ++i) {
                            var widget = line.widgets[i];
                            if (widget.node == n.firstChild) {
                                if (!widget.above && !insertBefore) insertBefore = n;
                                positionLineWidget(widget, n, reuse, dims);
                                ++widgetsSeen;
                                break;
                            }
                        }
                        if (i == line.widgets.length) { isOk = false; break; }
                    }
                }
                reuse.insertBefore(lineElement, insertBefore);
                if (isOk && widgetsSeen == line.widgets.length) {
                    wrap = reuse;
                    reuse.className = line.wrapClass || "";
                }
            }
            if (!wrap) {
                wrap = elt("div", null, line.wrapClass, "position: relative");
                wrap.appendChild(lineElement);
            }
            // Kludge to make sure the styled element lies behind the selection (by z-index)
            if (line.bgClass)
                wrap.insertBefore(elt("div", null, line.bgClass + " CodeMirror-linebackground"), wrap.firstChild);
            if (cm.options.lineNumbers || markers) {
                var gutterWrap = wrap.insertBefore(elt("div", null, null, "position: absolute; left: " +
                        (cm.options.fixedGutter ? dims.fixedPos : -dims.gutterTotalWidth) + "px"),
                    wrap.firstChild);
                if (cm.options.fixedGutter) (wrap.alignable || (wrap.alignable = [])).push(gutterWrap);
                if (cm.options.lineNumbers && (!markers || !markers["CodeMirror-linenumbers"]))
                    wrap.lineNumber = gutterWrap.appendChild(
                        elt("div", lineNumberFor(cm.options, lineNo),
                            "CodeMirror-linenumber CodeMirror-gutter-elt",
                                "left: " + dims.gutterLeft["CodeMirror-linenumbers"] + "px; width: "
                                + display.lineNumInnerWidth + "px"));
                if (markers)
                    for (var k = 0; k < cm.options.gutters.length; ++k) {
                        var id = cm.options.gutters[k], found = markers.hasOwnProperty(id) && markers[id];
                        if (found)
                            gutterWrap.appendChild(elt("div", [found], "CodeMirror-gutter-elt", "left: " +
                                dims.gutterLeft[id] + "px; width: " + dims.gutterWidth[id] + "px"));
                    }
            }
            if (ie_lt8) wrap.style.zIndex = 2;
            if (line.widgets && wrap != reuse) for (var i = 0, ws = line.widgets; i < ws.length; ++i) {
                var widget = ws[i], node = elt("div", [widget.node], "CodeMirror-linewidget");
                if (!widget.handleMouseEvents) node.ignoreEvents = true;
                positionLineWidget(widget, node, wrap, dims);
                if (widget.above)
                    wrap.insertBefore(node, cm.options.lineNumbers && line.height != 0 ? gutterWrap : lineElement);
                else
                    wrap.appendChild(node);
                signalLater(widget, "redraw");
            }
            return wrap;
        }

        function positionLineWidget(widget, node, wrap, dims) {
            if (widget.noHScroll) {
                (wrap.alignable || (wrap.alignable = [])).push(node);
                var width = dims.wrapperWidth;
                node.style.left = dims.fixedPos + "px";
                if (!widget.coverGutter) {
                    width -= dims.gutterTotalWidth;
                    node.style.paddingLeft = dims.gutterTotalWidth + "px";
                }
                node.style.width = width + "px";
            }
            if (widget.coverGutter) {
                node.style.zIndex = 5;
                node.style.position = "relative";
                if (!widget.noHScroll) node.style.marginLeft = -dims.gutterTotalWidth + "px";
            }
        }

        // SELECTION / CURSOR

        function updateSelection(cm) {
            var display = cm.display;
            var collapsed = posEq(cm.doc.sel.from, cm.doc.sel.to);
            if (collapsed || cm.options.showCursorWhenSelecting)
                updateSelectionCursor(cm);
            else
                display.cursor.style.display = display.otherCursor.style.display = "none";
            if (!collapsed)
                updateSelectionRange(cm);
            else
                display.selectionDiv.style.display = "none";

            // Move the hidden textarea near the cursor to prevent scrolling artifacts
            if (cm.options.moveInputWithCursor) {
                var headPos = cursorCoords(cm, cm.doc.sel.head, "div");
                var wrapOff = getRect(display.wrapper), lineOff = getRect(display.lineDiv);
                display.inputDiv.style.top = Math.max(0, Math.min(display.wrapper.clientHeight - 10,
                        headPos.top + lineOff.top - wrapOff.top)) + "px";
                display.inputDiv.style.left = Math.max(0, Math.min(display.wrapper.clientWidth - 10,
                        headPos.left + lineOff.left - wrapOff.left)) + "px";
            }
        }

        // No selection, plain cursor
        function updateSelectionCursor(cm) {
            var display = cm.display, pos = cursorCoords(cm, cm.doc.sel.head, "div");
            display.cursor.style.left = pos.left + "px";
            display.cursor.style.top = pos.top + "px";
            display.cursor.style.height = Math.max(0, pos.bottom - pos.top) * cm.options.cursorHeight + "px";
            display.cursor.style.display = "";

            if (pos.other) {
                display.otherCursor.style.display = "";
                display.otherCursor.style.left = pos.other.left + "px";
                display.otherCursor.style.top = pos.other.top + "px";
                display.otherCursor.style.height = (pos.other.bottom - pos.other.top) * .85 + "px";
            } else { display.otherCursor.style.display = "none"; }
        }

        // Highlight selection
        function updateSelectionRange(cm) {
            var display = cm.display, doc = cm.doc, sel = cm.doc.sel;
            var fragment = document.createDocumentFragment();
            var clientWidth = display.lineSpace.offsetWidth, pl = paddingLeft(cm.display);

            function add(left, top, width, bottom) {
                if (top < 0) top = 0;
                fragment.appendChild(elt("div", null, "CodeMirror-selected", "position: absolute; left: " + left +
                    "px; top: " + top + "px; width: " + (width == null ? clientWidth - left : width) +
                    "px; height: " + (bottom - top) + "px"));
            }

            function drawForLine(line, fromArg, toArg) {
                var lineObj = getLine(doc, line);
                var lineLen = lineObj.text.length;
                var start, end;
                function coords(ch, bias) {
                    return charCoords(cm, Pos(line, ch), "div", lineObj, bias);
                }

                iterateBidiSections(getOrder(lineObj), fromArg || 0, toArg == null ? lineLen : toArg, function(from, to, dir) {
                    var leftPos = coords(from, "left"), rightPos, left, right;
                    if (from == to) {
                        rightPos = leftPos;
                        left = right = leftPos.left;
                    } else {
                        rightPos = coords(to - 1, "right");
                        if (dir == "rtl") { var tmp = leftPos; leftPos = rightPos; rightPos = tmp; }
                        left = leftPos.left;
                        right = rightPos.right;
                    }
                    if (fromArg == null && from == 0) left = pl;
                    if (rightPos.top - leftPos.top > 3) { // Different lines, draw top part
                        add(left, leftPos.top, null, leftPos.bottom);
                        left = pl;
                        if (leftPos.bottom < rightPos.top) add(left, leftPos.bottom, null, rightPos.top);
                    }
                    if (toArg == null && to == lineLen) right = clientWidth;
                    if (!start || leftPos.top < start.top || leftPos.top == start.top && leftPos.left < start.left)
                        start = leftPos;
                    if (!end || rightPos.bottom > end.bottom || rightPos.bottom == end.bottom && rightPos.right > end.right)
                        end = rightPos;
                    if (left < pl + 1) left = pl;
                    add(left, rightPos.top, right - left, rightPos.bottom);
                });
                return {start: start, end: end};
            }

            if (sel.from.line == sel.to.line) {
                drawForLine(sel.from.line, sel.from.ch, sel.to.ch);
            } else {
                var fromLine = getLine(doc, sel.from.line), toLine = getLine(doc, sel.to.line);
                var singleVLine = visualLine(doc, fromLine) == visualLine(doc, toLine);
                var leftEnd = drawForLine(sel.from.line, sel.from.ch, singleVLine ? fromLine.text.length : null).end;
                var rightStart = drawForLine(sel.to.line, singleVLine ? 0 : null, sel.to.ch).start;
                if (singleVLine) {
                    if (leftEnd.top < rightStart.top - 2) {
                        add(leftEnd.right, leftEnd.top, null, leftEnd.bottom);
                        add(pl, rightStart.top, rightStart.left, rightStart.bottom);
                    } else {
                        add(leftEnd.right, leftEnd.top, rightStart.left - leftEnd.right, leftEnd.bottom);
                    }
                }
                if (leftEnd.bottom < rightStart.top)
                    add(pl, leftEnd.bottom, null, rightStart.top);
            }

            removeChildrenAndAdd(display.selectionDiv, fragment);
            display.selectionDiv.style.display = "";
        }

        // Cursor-blinking
        function restartBlink(cm) {
            if (!cm.state.focused) return;
            var display = cm.display;
            clearInterval(display.blinker);
            var on = true;
            display.cursor.style.visibility = display.otherCursor.style.visibility = "";
            display.blinker = setInterval(function() {
                display.cursor.style.visibility = display.otherCursor.style.visibility = (on = !on) ? "" : "hidden";
            }, cm.options.cursorBlinkRate);
        }

        // HIGHLIGHT WORKER

        function startWorker(cm, time) {
            if (cm.doc.mode.startState && cm.doc.frontier < cm.display.showingTo)
                cm.state.highlight.set(time, bind(highlightWorker, cm));
        }

        function highlightWorker(cm) {
            var doc = cm.doc;
            if (doc.frontier < doc.first) doc.frontier = doc.first;
            if (doc.frontier >= cm.display.showingTo) return;
            var end = +new Date + cm.options.workTime;
            var state = copyState(doc.mode, getStateBefore(cm, doc.frontier));
            var changed = [], prevChange;
            doc.iter(doc.frontier, Math.min(doc.first + doc.size, cm.display.showingTo + 500), function(line) {
                if (doc.frontier >= cm.display.showingFrom) { // Visible
                    var oldStyles = line.styles;
                    line.styles = highlightLine(cm, line, state);
                    var ischange = !oldStyles || oldStyles.length != line.styles.length;
                    for (var i = 0; !ischange && i < oldStyles.length; ++i) ischange = oldStyles[i] != line.styles[i];
                    if (ischange) {
                        if (prevChange && prevChange.end == doc.frontier) prevChange.end++;
                        else changed.push(prevChange = {start: doc.frontier, end: doc.frontier + 1});
                    }
                    line.stateAfter = copyState(doc.mode, state);
                } else {
                    processLine(cm, line, state);
                    line.stateAfter = doc.frontier % 5 == 0 ? copyState(doc.mode, state) : null;
                }
                ++doc.frontier;
                if (+new Date > end) {
                    startWorker(cm, cm.options.workDelay);
                    return true;
                }
            });
            if (changed.length)
                operation(cm, function() {
                    for (var i = 0; i < changed.length; ++i)
                        regChange(this, changed[i].start, changed[i].end);
                })();
        }

        // Finds the line to start with when starting a parse. Tries to
        // find a line with a stateAfter, so that it can start with a
        // valid state. If that fails, it returns the line with the
        // smallest indentation, which tends to need the least context to
        // parse correctly.
        function findStartLine(cm, n, precise) {
            var minindent, minline, doc = cm.doc;
            for (var search = n, lim = n - 100; search > lim; --search) {
                if (search <= doc.first) return doc.first;
                var line = getLine(doc, search - 1);
                if (line.stateAfter && (!precise || search <= doc.frontier)) return search;
                var indented = countColumn(line.text, null, cm.options.tabSize);
                if (minline == null || minindent > indented) {
                    minline = search - 1;
                    minindent = indented;
                }
            }
            return minline;
        }

        function getStateBefore(cm, n, precise) {
            var doc = cm.doc, display = cm.display;
            if (!doc.mode.startState) return true;
            var pos = findStartLine(cm, n, precise), state = pos > doc.first && getLine(doc, pos-1).stateAfter;
            if (!state) state = startState(doc.mode);
            else state = copyState(doc.mode, state);
            doc.iter(pos, n, function(line) {
                processLine(cm, line, state);
                var save = pos == n - 1 || pos % 5 == 0 || pos >= display.showingFrom && pos < display.showingTo;
                line.stateAfter = save ? copyState(doc.mode, state) : null;
                ++pos;
            });
            return state;
        }

        // POSITION MEASUREMENT

        function paddingTop(display) {return display.lineSpace.offsetTop;}
        function paddingVert(display) {return display.mover.offsetHeight - display.lineSpace.offsetHeight;}
        function paddingLeft(display) {
            var e = removeChildrenAndAdd(display.measure, elt("pre", null, null, "text-align: left")).appendChild(elt("span", "x"));
            return e.offsetLeft;
        }

        function measureChar(cm, line, ch, data, bias) {
            var dir = -1;
            data = data || measureLine(cm, line);

            for (var pos = ch;; pos += dir) {
                var r = data[pos];
                if (r) break;
                if (dir < 0 && pos == 0) dir = 1;
            }
            bias = pos > ch ? "left" : pos < ch ? "right" : bias;
            if (bias == "left" && r.leftSide) r = r.leftSide;
            else if (bias == "right" && r.rightSide) r = r.rightSide;
            return {left: pos < ch ? r.right : r.left,
                right: pos > ch ? r.left : r.right,
                top: r.top,
                bottom: r.bottom};
        }

        function findCachedMeasurement(cm, line) {
            var cache = cm.display.measureLineCache;
            for (var i = 0; i < cache.length; ++i) {
                var memo = cache[i];
                if (memo.text == line.text && memo.markedSpans == line.markedSpans &&
                    cm.display.scroller.clientWidth == memo.width &&
                    memo.classes == line.textClass + "|" + line.bgClass + "|" + line.wrapClass)
                    return memo;
            }
        }

        function clearCachedMeasurement(cm, line) {
            var exists = findCachedMeasurement(cm, line);
            if (exists) exists.text = exists.measure = exists.markedSpans = null;
        }

        function measureLine(cm, line) {
            // First look in the cache
            var cached = findCachedMeasurement(cm, line);
            if (cached) return cached.measure;

            // Failing that, recompute and store result in cache
            var measure = measureLineInner(cm, line);
            var cache = cm.display.measureLineCache;
            var memo = {text: line.text, width: cm.display.scroller.clientWidth,
                markedSpans: line.markedSpans, measure: measure,
                classes: line.textClass + "|" + line.bgClass + "|" + line.wrapClass};
            if (cache.length == 16) cache[++cm.display.measureLineCachePos % 16] = memo;
            else cache.push(memo);
            return measure;
        }

        function measureLineInner(cm, line) {
            var display = cm.display, measure = emptyArray(line.text.length);
            var pre = lineContent(cm, line, measure, true);

            // IE does not cache element positions of inline elements between
            // calls to getBoundingClientRect. This makes the loop below,
            // which gathers the positions of all the characters on the line,
            // do an amount of layout work quadratic to the number of
            // characters. When line wrapping is off, we try to improve things
            // by first subdividing the line into a bunch of inline blocks, so
            // that IE can reuse most of the layout information from caches
            // for those blocks. This does interfere with line wrapping, so it
            // doesn't work when wrapping is on, but in that case the
            // situation is slightly better, since IE does cache line-wrapping
            // information and only recomputes per-line.
            if (ie && !ie_lt8 && !cm.options.lineWrapping && pre.childNodes.length > 100) {
                var fragment = document.createDocumentFragment();
                var chunk = 10, n = pre.childNodes.length;
                for (var i = 0, chunks = Math.ceil(n / chunk); i < chunks; ++i) {
                    var wrap = elt("div", null, null, "display: inline-block");
                    for (var j = 0; j < chunk && n; ++j) {
                        wrap.appendChild(pre.firstChild);
                        --n;
                    }
                    fragment.appendChild(wrap);
                }
                pre.appendChild(fragment);
            }

            removeChildrenAndAdd(display.measure, pre);

            var outer = getRect(display.lineDiv);
            var vranges = [], data = emptyArray(line.text.length), maxBot = pre.offsetHeight;
            // Work around an IE7/8 bug where it will sometimes have randomly
            // replaced our pre with a clone at this point.
            if (ie_lt9 && display.measure.first != pre)
                removeChildrenAndAdd(display.measure, pre);

            function measureRect(rect) {
                var top = rect.top - outer.top, bot = rect.bottom - outer.top;
                if (bot > maxBot) bot = maxBot;
                if (top < 0) top = 0;
                for (var i = vranges.length - 2; i >= 0; i -= 2) {
                    var rtop = vranges[i], rbot = vranges[i+1];
                    if (rtop > bot || rbot < top) continue;
                    if (rtop <= top && rbot >= bot ||
                        top <= rtop && bot >= rbot ||
                        Math.min(bot, rbot) - Math.max(top, rtop) >= (bot - top) >> 1) {
                        vranges[i] = Math.min(top, rtop);
                        vranges[i+1] = Math.max(bot, rbot);
                        break;
                    }
                }
                if (i < 0) { i = vranges.length; vranges.push(top, bot); }
                return {left: rect.left - outer.left,
                    right: rect.right - outer.left,
                    top: i, bottom: null};
            }
            function finishRect(rect) {
                rect.bottom = vranges[rect.top+1];
                rect.top = vranges[rect.top];
            }

            for (var i = 0, cur; i < measure.length; ++i) if (cur = measure[i]) {
                var node = cur, rect = null;
                // A widget might wrap, needs special care
                if (/\bCodeMirror-widget\b/.test(cur.className) && cur.getClientRects) {
                    if (cur.firstChild.nodeType == 1) node = cur.firstChild;
                    var rects = node.getClientRects();
                    if (rects.length > 1) {
                        rect = data[i] = measureRect(rects[0]);
                        rect.rightSide = measureRect(rects[rects.length - 1]);
                    }
                }
                if (!rect) rect = data[i] = measureRect(getRect(node));
                if (cur.measureRight) rect.right = getRect(cur.measureRight).left;
                if (cur.leftSide) rect.leftSide = measureRect(getRect(cur.leftSide));
            }
            for (var i = 0, cur; i < data.length; ++i) if (cur = data[i]) {
                finishRect(cur);
                if (cur.leftSide) finishRect(cur.leftSide);
                if (cur.rightSide) finishRect(cur.rightSide);
            }
            return data;
        }

        function measureLineWidth(cm, line) {
            var hasBadSpan = false;
            if (line.markedSpans) for (var i = 0; i < line.markedSpans; ++i) {
                var sp = line.markedSpans[i];
                if (sp.collapsed && (sp.to == null || sp.to == line.text.length)) hasBadSpan = true;
            }
            var cached = !hasBadSpan && findCachedMeasurement(cm, line);
            if (cached) return measureChar(cm, line, line.text.length, cached.measure, "right").right;

            var pre = lineContent(cm, line, null, true);
            var end = pre.appendChild(zeroWidthElement(cm.display.measure));
            removeChildrenAndAdd(cm.display.measure, pre);
            return getRect(end).right - getRect(cm.display.lineDiv).left;
        }

        function clearCaches(cm) {
            cm.display.measureLineCache.length = cm.display.measureLineCachePos = 0;
            cm.display.cachedCharWidth = cm.display.cachedTextHeight = null;
            if (!cm.options.lineWrapping) cm.display.maxLineChanged = true;
            cm.display.lineNumChars = null;
        }

        function pageScrollX() { return window.pageXOffset || (document.documentElement || document.body).scrollLeft; }
        function pageScrollY() { return window.pageYOffset || (document.documentElement || document.body).scrollTop; }

        // Context is one of "line", "div" (display.lineDiv), "local"/null (editor), or "page"
        function intoCoordSystem(cm, lineObj, rect, context) {
            if (lineObj.widgets) for (var i = 0; i < lineObj.widgets.length; ++i) if (lineObj.widgets[i].above) {
                var size = widgetHeight(lineObj.widgets[i]);
                rect.top += size; rect.bottom += size;
            }
            if (context == "line") return rect;
            if (!context) context = "local";
            var yOff = heightAtLine(cm, lineObj);
            if (context == "local") yOff += paddingTop(cm.display);
            else yOff -= cm.display.viewOffset;
            if (context == "page" || context == "window") {
                var lOff = getRect(cm.display.lineSpace);
                yOff += lOff.top + (context == "window" ? 0 : pageScrollY());
                var xOff = lOff.left + (context == "window" ? 0 : pageScrollX());
                rect.left += xOff; rect.right += xOff;
            }
            rect.top += yOff; rect.bottom += yOff;
            return rect;
        }

        // Context may be "window", "page", "div", or "local"/null
        // Result is in "div" coords
        function fromCoordSystem(cm, coords, context) {
            if (context == "div") return coords;
            var left = coords.left, top = coords.top;
            // First move into "page" coordinate system
            if (context == "page") {
                left -= pageScrollX();
                top -= pageScrollY();
            } else if (context == "local" || !context) {
                var localBox = getRect(cm.display.sizer);
                left += localBox.left;
                top += localBox.top;
            }

            var lineSpaceBox = getRect(cm.display.lineSpace);
            return {left: left - lineSpaceBox.left, top: top - lineSpaceBox.top};
        }

        function charCoords(cm, pos, context, lineObj, bias) {
            if (!lineObj) lineObj = getLine(cm.doc, pos.line);
            return intoCoordSystem(cm, lineObj, measureChar(cm, lineObj, pos.ch, null, bias), context);
        }

        function cursorCoords(cm, pos, context, lineObj, measurement) {
            lineObj = lineObj || getLine(cm.doc, pos.line);
            if (!measurement) measurement = measureLine(cm, lineObj);
            function get(ch, right) {
                var m = measureChar(cm, lineObj, ch, measurement, right ? "right" : "left");
                if (right) m.left = m.right; else m.right = m.left;
                return intoCoordSystem(cm, lineObj, m, context);
            }
            function getBidi(ch, partPos) {
                var part = order[partPos], right = part.level % 2;
                if (ch == bidiLeft(part) && partPos && part.level < order[partPos - 1].level) {
                    part = order[--partPos];
                    ch = bidiRight(part) - (part.level % 2 ? 0 : 1);
                    right = true;
                } else if (ch == bidiRight(part) && partPos < order.length - 1 && part.level < order[partPos + 1].level) {
                    part = order[++partPos];
                    ch = bidiLeft(part) - part.level % 2;
                    right = false;
                }
                if (right && ch == part.to && ch > part.from) return get(ch - 1);
                return get(ch, right);
            }
            var order = getOrder(lineObj), ch = pos.ch;
            if (!order) return get(ch);
            var partPos = getBidiPartAt(order, ch);
            var val = getBidi(ch, partPos);
            if (bidiOther != null) val.other = getBidi(ch, bidiOther);
            return val;
        }

        function PosWithInfo(line, ch, outside, xRel) {
            var pos = new Pos(line, ch);
            pos.xRel = xRel;
            if (outside) pos.outside = true;
            return pos;
        }

        // Coords must be lineSpace-local
        function coordsChar(cm, x, y) {
            var doc = cm.doc;
            y += cm.display.viewOffset;
            if (y < 0) return PosWithInfo(doc.first, 0, true, -1);
            var lineNo = lineAtHeight(doc, y), last = doc.first + doc.size - 1;
            if (lineNo > last)
                return PosWithInfo(doc.first + doc.size - 1, getLine(doc, last).text.length, true, 1);
            if (x < 0) x = 0;

            for (;;) {
                var lineObj = getLine(doc, lineNo);
                var found = coordsCharInner(cm, lineObj, lineNo, x, y);
                var merged = collapsedSpanAtEnd(lineObj);
                var mergedPos = merged && merged.find();
                if (merged && (found.ch > mergedPos.from.ch || found.ch == mergedPos.from.ch && found.xRel > 0))
                    lineNo = mergedPos.to.line;
                else
                    return found;
            }
        }

        function coordsCharInner(cm, lineObj, lineNo, x, y) {
            var innerOff = y - heightAtLine(cm, lineObj);
            var wrongLine = false, adjust = 2 * cm.display.wrapper.clientWidth;
            var measurement = measureLine(cm, lineObj);

            function getX(ch) {
                var sp = cursorCoords(cm, Pos(lineNo, ch), "line",
                    lineObj, measurement);
                wrongLine = true;
                if (innerOff > sp.bottom) return sp.left - adjust;
                else if (innerOff < sp.top) return sp.left + adjust;
                else wrongLine = false;
                return sp.left;
            }

            var bidi = getOrder(lineObj), dist = lineObj.text.length;
            var from = lineLeft(lineObj), to = lineRight(lineObj);
            var fromX = getX(from), fromOutside = wrongLine, toX = getX(to), toOutside = wrongLine;

            if (x > toX) return PosWithInfo(lineNo, to, toOutside, 1);
            // Do a binary search between these bounds.
            for (;;) {
                if (bidi ? to == from || to == moveVisually(lineObj, from, 1) : to - from <= 1) {
                    var ch = x < fromX || x - fromX <= toX - x ? from : to;
                    var xDiff = x - (ch == from ? fromX : toX);
                    while (isExtendingChar.test(lineObj.text.charAt(ch))) ++ch;
                    var pos = PosWithInfo(lineNo, ch, ch == from ? fromOutside : toOutside,
                            xDiff < 0 ? -1 : xDiff ? 1 : 0);
                    return pos;
                }
                var step = Math.ceil(dist / 2), middle = from + step;
                if (bidi) {
                    middle = from;
                    for (var i = 0; i < step; ++i) middle = moveVisually(lineObj, middle, 1);
                }
                var middleX = getX(middle);
                if (middleX > x) {to = middle; toX = middleX; if (toOutside = wrongLine) toX += 1000; dist = step;}
                else {from = middle; fromX = middleX; fromOutside = wrongLine; dist -= step;}
            }
        }

        var measureText;
        function textHeight(display) {
            if (display.cachedTextHeight != null) return display.cachedTextHeight;
            if (measureText == null) {
                measureText = elt("pre");
                // Measure a bunch of lines, for browsers that compute
                // fractional heights.
                for (var i = 0; i < 49; ++i) {
                    measureText.appendChild(document.createTextNode("x"));
                    measureText.appendChild(elt("br"));
                }
                measureText.appendChild(document.createTextNode("x"));
            }
            removeChildrenAndAdd(display.measure, measureText);
            var height = measureText.offsetHeight / 50;
            if (height > 3) display.cachedTextHeight = height;
            removeChildren(display.measure);
            return height || 1;
        }

        function charWidth(display) {
            if (display.cachedCharWidth != null) return display.cachedCharWidth;
            var anchor = elt("span", "x");
            var pre = elt("pre", [anchor]);
            removeChildrenAndAdd(display.measure, pre);
            var width = anchor.offsetWidth;
            if (width > 2) display.cachedCharWidth = width;
            return width || 10;
        }

        // OPERATIONS

        // Operations are used to wrap changes in such a way that each
        // change won't have to update the cursor and display (which would
        // be awkward, slow, and error-prone), but instead updates are
        // batched and then all combined and executed at once.

        var nextOpId = 0;
        function startOperation(cm) {
            cm.curOp = {
                // An array of ranges of lines that have to be updated. See
                // updateDisplay.
                changes: [],
                forceUpdate: false,
                updateInput: null,
                userSelChange: null,
                textChanged: null,
                selectionChanged: false,
                cursorActivity: false,
                updateMaxLine: false,
                updateScrollPos: false,
                id: ++nextOpId
            };
            if (!delayedCallbackDepth++) delayedCallbacks = [];
        }

        function endOperation(cm) {
            var op = cm.curOp, doc = cm.doc, display = cm.display;
            cm.curOp = null;

            if (op.updateMaxLine) computeMaxLength(cm);
            if (display.maxLineChanged && !cm.options.lineWrapping && display.maxLine) {
                var width = measureLineWidth(cm, display.maxLine);
                display.sizer.style.minWidth = Math.max(0, width + 3 + scrollerCutOff) + "px";
                display.maxLineChanged = false;
                var maxScrollLeft = Math.max(0, display.sizer.offsetLeft + display.sizer.offsetWidth - display.scroller.clientWidth);
                if (maxScrollLeft < doc.scrollLeft && !op.updateScrollPos)
                    setScrollLeft(cm, Math.min(display.scroller.scrollLeft, maxScrollLeft), true);
            }
            var newScrollPos, updated;
            if (op.updateScrollPos) {
                newScrollPos = op.updateScrollPos;
            } else if (op.selectionChanged && display.scroller.clientHeight) { // don't rescroll if not visible
                var coords = cursorCoords(cm, doc.sel.head);
                newScrollPos = calculateScrollPos(cm, coords.left, coords.top, coords.left, coords.bottom);
            }
            if (op.changes.length || op.forceUpdate || newScrollPos && newScrollPos.scrollTop != null) {
                updated = updateDisplay(cm, op.changes, newScrollPos && newScrollPos.scrollTop, op.forceUpdate);
                if (cm.display.scroller.offsetHeight) cm.doc.scrollTop = cm.display.scroller.scrollTop;
            }
            if (!updated && op.selectionChanged) updateSelection(cm);
            if (op.updateScrollPos) {
                display.scroller.scrollTop = display.scrollbarV.scrollTop = doc.scrollTop = newScrollPos.scrollTop;
                display.scroller.scrollLeft = display.scrollbarH.scrollLeft = doc.scrollLeft = newScrollPos.scrollLeft;
                alignHorizontally(cm);
                if (op.scrollToPos)
                    scrollPosIntoView(cm, clipPos(cm.doc, op.scrollToPos), op.scrollToPosMargin);
            } else if (newScrollPos) {
                scrollCursorIntoView(cm);
            }
            if (op.selectionChanged) restartBlink(cm);

            if (cm.state.focused && op.updateInput)
                resetInput(cm, op.userSelChange);

            var hidden = op.maybeHiddenMarkers, unhidden = op.maybeUnhiddenMarkers;
            if (hidden) for (var i = 0; i < hidden.length; ++i)
                if (!hidden[i].lines.length) signal(hidden[i], "hide");
            if (unhidden) for (var i = 0; i < unhidden.length; ++i)
                if (unhidden[i].lines.length) signal(unhidden[i], "unhide");

            var delayed;
            if (!--delayedCallbackDepth) {
                delayed = delayedCallbacks;
                delayedCallbacks = null;
            }
            if (op.textChanged)
                signal(cm, "change", cm, op.textChanged);
            if (op.cursorActivity) signal(cm, "cursorActivity", cm);
            if (delayed) for (var i = 0; i < delayed.length; ++i) delayed[i]();
        }

        // Wraps a function in an operation. Returns the wrapped function.
        function operation(cm1, f) {
            return function() {
                var cm = cm1 || this, withOp = !cm.curOp;
                if (withOp) startOperation(cm);
                try { var result = f.apply(cm, arguments); }
                finally { if (withOp) endOperation(cm); }
                return result;
            };
        }
        function docOperation(f) {
            return function() {
                var withOp = this.cm && !this.cm.curOp, result;
                if (withOp) startOperation(this.cm);
                try { result = f.apply(this, arguments); }
                finally { if (withOp) endOperation(this.cm); }
                return result;
            };
        }
        function runInOp(cm, f) {
            var withOp = !cm.curOp, result;
            if (withOp) startOperation(cm);
            try { result = f(); }
            finally { if (withOp) endOperation(cm); }
            return result;
        }

        function regChange(cm, from, to, lendiff) {
            if (from == null) from = cm.doc.first;
            if (to == null) to = cm.doc.first + cm.doc.size;
            cm.curOp.changes.push({from: from, to: to, diff: lendiff});
        }

        // INPUT HANDLING

        function slowPoll(cm) {
            if (cm.display.pollingFast) return;
            cm.display.poll.set(cm.options.pollInterval, function() {
                readInput(cm);
                if (cm.state.focused) slowPoll(cm);
            });
        }

        function fastPoll(cm) {
            var missed = false;
            cm.display.pollingFast = true;
            function p() {
                var changed = readInput(cm);
                if (!changed && !missed) {missed = true; cm.display.poll.set(60, p);}
                else {cm.display.pollingFast = false; slowPoll(cm);}
            }
            cm.display.poll.set(20, p);
        }

        // prevInput is a hack to work with IME. If we reset the textarea
        // on every change, that breaks IME. So we look for changes
        // compared to the previous content instead. (Modern browsers have
        // events that indicate IME taking place, but these are not widely
        // supported or compatible enough yet to rely on.)
        function readInput(cm) {
            var input = cm.display.input, prevInput = cm.display.prevInput, doc = cm.doc, sel = doc.sel;
            if (!cm.state.focused || hasSelection(input) || isReadOnly(cm) || cm.state.disableInput) return false;
            var text = input.value;
            if (text == prevInput && posEq(sel.from, sel.to)) return false;
            if (ie && !ie_lt9 && cm.display.inputHasSelection === text) {
                resetInput(cm, true);
                return false;
            }

            var withOp = !cm.curOp;
            if (withOp) startOperation(cm);
            sel.shift = false;
            var same = 0, l = Math.min(prevInput.length, text.length);
            while (same < l && prevInput.charCodeAt(same) == text.charCodeAt(same)) ++same;
            var from = sel.from, to = sel.to;
            if (same < prevInput.length)
                from = Pos(from.line, from.ch - (prevInput.length - same));
            else if (cm.state.overwrite && posEq(from, to) && !cm.state.pasteIncoming)
                to = Pos(to.line, Math.min(getLine(doc, to.line).text.length, to.ch + (text.length - same)));

            var updateInput = cm.curOp.updateInput;
            var changeEvent = {from: from, to: to, text: splitLines(text.slice(same)),
                origin: cm.state.pasteIncoming ? "paste" : "+input"};
            makeChange(cm.doc, changeEvent, "end");
            cm.curOp.updateInput = updateInput;
            signalLater(cm, "inputRead", cm, changeEvent);

            if (text.length > 1000 || text.indexOf("\n") > -1) input.value = cm.display.prevInput = "";
            else cm.display.prevInput = text;
            if (withOp) endOperation(cm);
            cm.state.pasteIncoming = false;
            return true;
        }

        function resetInput(cm, user) {
            var minimal, selected, doc = cm.doc;
            if (!posEq(doc.sel.from, doc.sel.to)) {
                cm.display.prevInput = "";
                minimal = hasCopyEvent &&
                    (doc.sel.to.line - doc.sel.from.line > 100 || (selected = cm.getSelection()).length > 1000);
                var content = minimal ? "-" : selected || cm.getSelection();
                cm.display.input.value = content;
                if (cm.state.focused) selectInput(cm.display.input);
                if (ie && !ie_lt9) cm.display.inputHasSelection = content;
            } else if (user) {
                cm.display.prevInput = cm.display.input.value = "";
                if (ie && !ie_lt9) cm.display.inputHasSelection = null;
            }
            cm.display.inaccurateSelection = minimal;
        }

        function focusInput(cm) {
            if (cm.options.readOnly != "nocursor" && (!mobile || document.activeElement != cm.display.input))
                try {cm.display.input.focus();} catch(e) {}
        }

        function isReadOnly(cm) {
            return cm.options.readOnly || cm.doc.cantEdit;
        }

        // EVENT HANDLERS

        function registerEventHandlers(cm) {
            var d = cm.display;
            on(d.scroller, "mousedown", operation(cm, onMouseDown));
            if (ie)
                on(d.scroller, "dblclick", operation(cm, function(e) {
                    if (signalDOMEvent(cm, e)) return;
                    var pos = posFromMouse(cm, e);
                    if (!pos || clickInGutter(cm, e) || eventInWidget(cm.display, e)) return;
                    e_preventDefault(e);
                    var word = findWordAt(getLine(cm.doc, pos.line).text, pos);
                    extendSelection(cm.doc, word.from, word.to);
                }));
            else
                on(d.scroller, "dblclick", function(e) { signalDOMEvent(cm, e) || e_preventDefault(e); });
            on(d.lineSpace, "selectstart", function(e) {
                if (!eventInWidget(d, e)) e_preventDefault(e);
            });
            // Gecko browsers fire contextmenu *after* opening the menu, at
            // which point we can't mess with it anymore. Context menu is
            // handled in onMouseDown for Gecko.
            if (!captureMiddleClick) on(d.scroller, "contextmenu", function(e) {onContextMenu(cm, e);});

            on(d.scroller, "scroll", function() {
                if (d.scroller.clientHeight) {
                    setScrollTop(cm, d.scroller.scrollTop);
                    setScrollLeft(cm, d.scroller.scrollLeft, true);
                    signal(cm, "scroll", cm);
                }
            });
            on(d.scrollbarV, "scroll", function() {
                if (d.scroller.clientHeight) setScrollTop(cm, d.scrollbarV.scrollTop);
            });
            on(d.scrollbarH, "scroll", function() {
                if (d.scroller.clientHeight) setScrollLeft(cm, d.scrollbarH.scrollLeft);
            });

            on(d.scroller, "mousewheel", function(e){onScrollWheel(cm, e);});
            on(d.scroller, "DOMMouseScroll", function(e){onScrollWheel(cm, e);});

            function reFocus() { if (cm.state.focused) setTimeout(bind(focusInput, cm), 0); }
            on(d.scrollbarH, "mousedown", reFocus);
            on(d.scrollbarV, "mousedown", reFocus);
            // Prevent wrapper from ever scrolling
            on(d.wrapper, "scroll", function() { d.wrapper.scrollTop = d.wrapper.scrollLeft = 0; });

            var resizeTimer;
            function onResize() {
                if (resizeTimer == null) resizeTimer = setTimeout(function() {
                    resizeTimer = null;
                    // Might be a text scaling operation, clear size caches.
                    d.cachedCharWidth = d.cachedTextHeight = knownScrollbarWidth = null;
                    clearCaches(cm);
                    runInOp(cm, bind(regChange, cm));
                }, 100);
            }
            on(window, "resize", onResize);
            // Above handler holds on to the editor and its data structures.
            // Here we poll to unregister it when the editor is no longer in
            // the document, so that it can be garbage-collected.
            function unregister() {
                for (var p = d.wrapper.parentNode; p && p != document.body; p = p.parentNode) {}
                if (p) setTimeout(unregister, 5000);
                else off(window, "resize", onResize);
            }
            setTimeout(unregister, 5000);

            on(d.input, "keyup", operation(cm, function(e) {
                if (signalDOMEvent(cm, e) || cm.options.onKeyEvent && cm.options.onKeyEvent(cm, addStop(e))) return;
                if (e.keyCode == 16) cm.doc.sel.shift = false;
            }));
            on(d.input, "input", bind(fastPoll, cm));
            on(d.input, "keydown", operation(cm, onKeyDown));
            on(d.input, "keypress", operation(cm, onKeyPress));
            on(d.input, "focus", bind(onFocus, cm));
            on(d.input, "blur", bind(onBlur, cm));

            function drag_(e) {
                if (signalDOMEvent(cm, e) || cm.options.onDragEvent && cm.options.onDragEvent(cm, addStop(e))) return;
                e_stop(e);
            }
            if (cm.options.dragDrop) {
                on(d.scroller, "dragstart", function(e){onDragStart(cm, e);});
                on(d.scroller, "dragenter", drag_);
                on(d.scroller, "dragover", drag_);
                on(d.scroller, "drop", operation(cm, onDrop));
            }
            on(d.scroller, "paste", function(e){
                if (eventInWidget(d, e)) return;
                focusInput(cm);
                fastPoll(cm);
            });
            on(d.input, "paste", function() {
                cm.state.pasteIncoming = true;
                fastPoll(cm);
            });

            function prepareCopy() {
                if (d.inaccurateSelection) {
                    d.prevInput = "";
                    d.inaccurateSelection = false;
                    d.input.value = cm.getSelection();
                    selectInput(d.input);
                }
            }
            on(d.input, "cut", prepareCopy);
            on(d.input, "copy", prepareCopy);

            // Needed to handle Tab key in KHTML
            if (khtml) on(d.sizer, "mouseup", function() {
                if (document.activeElement == d.input) d.input.blur();
                focusInput(cm);
            });
        }

        function eventInWidget(display, e) {
            for (var n = e_target(e); n != display.wrapper; n = n.parentNode) {
                if (!n || n.ignoreEvents || n.parentNode == display.sizer && n != display.mover) return true;
            }
        }

        function posFromMouse(cm, e, liberal) {
            var display = cm.display;
            if (!liberal) {
                var target = e_target(e);
                if (target == display.scrollbarH || target == display.scrollbarH.firstChild ||
                    target == display.scrollbarV || target == display.scrollbarV.firstChild ||
                    target == display.scrollbarFiller || target == display.gutterFiller) return null;
            }
            var x, y, space = getRect(display.lineSpace);
            // Fails unpredictably on IE[67] when mouse is dragged around quickly.
            try { x = e.clientX; y = e.clientY; } catch (e) { return null; }
            return coordsChar(cm, x - space.left, y - space.top);
        }

        var lastClick, lastDoubleClick;
        function onMouseDown(e) {
            if (signalDOMEvent(this, e)) return;
            var cm = this, display = cm.display, doc = cm.doc, sel = doc.sel;
            sel.shift = e.shiftKey;

            if (eventInWidget(display, e)) {
                if (!webkit) {
                    display.scroller.draggable = false;
                    setTimeout(function(){display.scroller.draggable = true;}, 100);
                }
                return;
            }
            if (clickInGutter(cm, e)) return;
            var start = posFromMouse(cm, e);

            switch (e_button(e)) {
                case 3:
                    if (captureMiddleClick) onContextMenu.call(cm, cm, e);
                    return;
                case 2:
                    if (start) extendSelection(cm.doc, start);
                    setTimeout(bind(focusInput, cm), 20);
                    e_preventDefault(e);
                    return;
            }
            // For button 1, if it was clicked inside the editor
            // (posFromMouse returning non-null), we have to adjust the
            // selection.
            if (!start) {if (e_target(e) == display.scroller) e_preventDefault(e); return;}

            if (!cm.state.focused) onFocus(cm);

            var now = +new Date, type = "single";
            if (lastDoubleClick && lastDoubleClick.time > now - 400 && posEq(lastDoubleClick.pos, start)) {
                type = "triple";
                e_preventDefault(e);
                setTimeout(bind(focusInput, cm), 20);
                selectLine(cm, start.line);
            } else if (lastClick && lastClick.time > now - 400 && posEq(lastClick.pos, start)) {
                type = "double";
                lastDoubleClick = {time: now, pos: start};
                e_preventDefault(e);
                var word = findWordAt(getLine(doc, start.line).text, start);
                extendSelection(cm.doc, word.from, word.to);
            } else { lastClick = {time: now, pos: start}; }

            var last = start;
            if (cm.options.dragDrop && dragAndDrop && !isReadOnly(cm) && !posEq(sel.from, sel.to) &&
                !posLess(start, sel.from) && !posLess(sel.to, start) && type == "single") {
                var dragEnd = operation(cm, function(e2) {
                    if (webkit) display.scroller.draggable = false;
                    cm.state.draggingText = false;
                    off(document, "mouseup", dragEnd);
                    off(display.scroller, "drop", dragEnd);
                    if (Math.abs(e.clientX - e2.clientX) + Math.abs(e.clientY - e2.clientY) < 10) {
                        e_preventDefault(e2);
                        extendSelection(cm.doc, start);
                        focusInput(cm);
                    }
                });
                // Let the drag handler handle this.
                if (webkit) display.scroller.draggable = true;
                cm.state.draggingText = dragEnd;
                // IE's approach to draggable
                if (display.scroller.dragDrop) display.scroller.dragDrop();
                on(document, "mouseup", dragEnd);
                on(display.scroller, "drop", dragEnd);
                return;
            }
            e_preventDefault(e);
            if (type == "single") extendSelection(cm.doc, clipPos(doc, start));

            var startstart = sel.from, startend = sel.to, lastPos = start;

            function doSelect(cur) {
                if (posEq(lastPos, cur)) return;
                lastPos = cur;

                if (type == "single") {
                    extendSelection(cm.doc, clipPos(doc, start), cur);
                    return;
                }

                startstart = clipPos(doc, startstart);
                startend = clipPos(doc, startend);
                if (type == "double") {
                    var word = findWordAt(getLine(doc, cur.line).text, cur);
                    if (posLess(cur, startstart)) extendSelection(cm.doc, word.from, startend);
                    else extendSelection(cm.doc, startstart, word.to);
                } else if (type == "triple") {
                    if (posLess(cur, startstart)) extendSelection(cm.doc, startend, clipPos(doc, Pos(cur.line, 0)));
                    else extendSelection(cm.doc, startstart, clipPos(doc, Pos(cur.line + 1, 0)));
                }
            }

            var editorSize = getRect(display.wrapper);
            // Used to ensure timeout re-tries don't fire when another extend
            // happened in the meantime (clearTimeout isn't reliable -- at
            // least on Chrome, the timeouts still happen even when cleared,
            // if the clear happens after their scheduled firing time).
            var counter = 0;

            function extend(e) {
                var curCount = ++counter;
                var cur = posFromMouse(cm, e, true);
                if (!cur) return;
                if (!posEq(cur, last)) {
                    if (!cm.state.focused) onFocus(cm);
                    last = cur;
                    doSelect(cur);
                    var visible = visibleLines(display, doc);
                    if (cur.line >= visible.to || cur.line < visible.from)
                        setTimeout(operation(cm, function(){if (counter == curCount) extend(e);}), 150);
                } else {
                    var outside = e.clientY < editorSize.top ? -20 : e.clientY > editorSize.bottom ? 20 : 0;
                    if (outside) setTimeout(operation(cm, function() {
                        if (counter != curCount) return;
                        display.scroller.scrollTop += outside;
                        extend(e);
                    }), 50);
                }
            }

            function done(e) {
                counter = Infinity;
                e_preventDefault(e);
                focusInput(cm);
                off(document, "mousemove", move);
                off(document, "mouseup", up);
            }

            var move = operation(cm, function(e) {
                if (!ie && !e_button(e)) done(e);
                else extend(e);
            });
            var up = operation(cm, done);
            on(document, "mousemove", move);
            on(document, "mouseup", up);
        }

        function clickInGutter(cm, e) {
            var display = cm.display;
            try { var mX = e.clientX, mY = e.clientY; }
            catch(e) { return false; }

            if (mX >= Math.floor(getRect(display.gutters).right)) return false;
            e_preventDefault(e);
            if (!hasHandler(cm, "gutterClick")) return true;

            var lineBox = getRect(display.lineDiv);
            if (mY > lineBox.bottom) return true;
            mY -= lineBox.top - display.viewOffset;

            for (var i = 0; i < cm.options.gutters.length; ++i) {
                var g = display.gutters.childNodes[i];
                if (g && getRect(g).right >= mX) {
                    var line = lineAtHeight(cm.doc, mY);
                    var gutter = cm.options.gutters[i];
                    signalLater(cm, "gutterClick", cm, line, gutter, e);
                    break;
                }
            }
            return true;
        }

        // Kludge to work around strange IE behavior where it'll sometimes
        // re-fire a series of drag-related events right after the drop (#1551)
        var lastDrop = 0;

        function onDrop(e) {
            var cm = this;
            if (signalDOMEvent(cm, e) || eventInWidget(cm.display, e) || (cm.options.onDragEvent && cm.options.onDragEvent(cm, addStop(e))))
                return;
            e_preventDefault(e);
            if (ie) lastDrop = +new Date;
            var pos = posFromMouse(cm, e, true), files = e.dataTransfer.files;
            if (!pos || isReadOnly(cm)) return;
            if (files && files.length && window.FileReader && window.File) {
                var n = files.length, text = Array(n), read = 0;
                var loadFile = function(file, i) {
                    var reader = new FileReader;
                    reader.onload = function() {
                        text[i] = reader.result;
                        if (++read == n) {
                            pos = clipPos(cm.doc, pos);
                            makeChange(cm.doc, {from: pos, to: pos, text: splitLines(text.join("\n")), origin: "paste"}, "around");
                        }
                    };
                    reader.readAsText(file);
                };
                for (var i = 0; i < n; ++i) loadFile(files[i], i);
            } else {
                // Don't do a replace if the drop happened inside of the selected text.
                if (cm.state.draggingText && !(posLess(pos, cm.doc.sel.from) || posLess(cm.doc.sel.to, pos))) {
                    cm.state.draggingText(e);
                    // Ensure the editor is re-focused
                    setTimeout(bind(focusInput, cm), 20);
                    return;
                }
                try {
                    var text = e.dataTransfer.getData("Text");
                    if (text) {
                        var curFrom = cm.doc.sel.from, curTo = cm.doc.sel.to;
                        setSelection(cm.doc, pos, pos);
                        if (cm.state.draggingText) replaceRange(cm.doc, "", curFrom, curTo, "paste");
                        cm.replaceSelection(text, null, "paste");
                        focusInput(cm);
                        onFocus(cm);
                    }
                }
                catch(e){}
            }
        }

        function onDragStart(cm, e) {
            if (ie && (!cm.state.draggingText || +new Date - lastDrop < 100)) { e_stop(e); return; }
            if (signalDOMEvent(cm, e) || eventInWidget(cm.display, e)) return;

            var txt = cm.getSelection();
            e.dataTransfer.setData("Text", txt);

            // Use dummy image instead of default browsers image.
            // Recent Safari (~6.0.2) have a tendency to segfault when this happens, so we don't do it there.
            if (e.dataTransfer.setDragImage && !safari) {
                var img = elt("img", null, null, "position: fixed; left: 0; top: 0;");
                if (opera) {
                    img.width = img.height = 1;
                    cm.display.wrapper.appendChild(img);
                    // Force a relayout, or Opera won't use our image for some obscure reason
                    img._top = img.offsetTop;
                }
                e.dataTransfer.setDragImage(img, 0, 0);
                if (opera) img.parentNode.removeChild(img);
            }
        }

        function setScrollTop(cm, val) {
            if (Math.abs(cm.doc.scrollTop - val) < 2) return;
            cm.doc.scrollTop = val;
            if (!gecko) updateDisplay(cm, [], val);
            if (cm.display.scroller.scrollTop != val) cm.display.scroller.scrollTop = val;
            if (cm.display.scrollbarV.scrollTop != val) cm.display.scrollbarV.scrollTop = val;
            if (gecko) updateDisplay(cm, []);
            startWorker(cm, 100);
        }
        function setScrollLeft(cm, val, isScroller) {
            if (isScroller ? val == cm.doc.scrollLeft : Math.abs(cm.doc.scrollLeft - val) < 2) return;
            val = Math.min(val, cm.display.scroller.scrollWidth - cm.display.scroller.clientWidth);
            cm.doc.scrollLeft = val;
            alignHorizontally(cm);
            if (cm.display.scroller.scrollLeft != val) cm.display.scroller.scrollLeft = val;
            if (cm.display.scrollbarH.scrollLeft != val) cm.display.scrollbarH.scrollLeft = val;
        }

        // Since the delta values reported on mouse wheel events are
        // unstandardized between browsers and even browser versions, and
        // generally horribly unpredictable, this code starts by measuring
        // the scroll effect that the first few mouse wheel events have,
        // and, from that, detects the way it can convert deltas to pixel
        // offsets afterwards.
        //
        // The reason we want to know the amount a wheel event will scroll
        // is that it gives us a chance to update the display before the
        // actual scrolling happens, reducing flickering.

        var wheelSamples = 0, wheelPixelsPerUnit = null;
        // Fill in a browser-detected starting value on browsers where we
        // know one. These don't have to be accurate -- the result of them
        // being wrong would just be a slight flicker on the first wheel
        // scroll (if it is large enough).
        if (ie) wheelPixelsPerUnit = -.53;
        else if (gecko) wheelPixelsPerUnit = 15;
        else if (chrome) wheelPixelsPerUnit = -.7;
        else if (safari) wheelPixelsPerUnit = -1/3;

        function onScrollWheel(cm, e) {
            var dx = e.wheelDeltaX, dy = e.wheelDeltaY;
            if (dx == null && e.detail && e.axis == e.HORIZONTAL_AXIS) dx = e.detail;
            if (dy == null && e.detail && e.axis == e.VERTICAL_AXIS) dy = e.detail;
            else if (dy == null) dy = e.wheelDelta;

            var display = cm.display, scroll = display.scroller;
            // Quit if there's nothing to scroll here
            if (!(dx && scroll.scrollWidth > scroll.clientWidth ||
                dy && scroll.scrollHeight > scroll.clientHeight)) return;

            // Webkit browsers on OS X abort momentum scrolls when the target
            // of the scroll event is removed from the scrollable element.
            // This hack (see related code in patchDisplay) makes sure the
            // element is kept around.
            if (dy && mac && webkit) {
                for (var cur = e.target; cur != scroll; cur = cur.parentNode) {
                    if (cur.lineObj) {
                        cm.display.currentWheelTarget = cur;
                        break;
                    }
                }
            }

            // On some browsers, horizontal scrolling will cause redraws to
            // happen before the gutter has been realigned, causing it to
            // wriggle around in a most unseemly way. When we have an
            // estimated pixels/delta value, we just handle horizontal
            // scrolling entirely here. It'll be slightly off from native, but
            // better than glitching out.
            if (dx && !gecko && !opera && wheelPixelsPerUnit != null) {
                if (dy)
                    setScrollTop(cm, Math.max(0, Math.min(scroll.scrollTop + dy * wheelPixelsPerUnit, scroll.scrollHeight - scroll.clientHeight)));
                setScrollLeft(cm, Math.max(0, Math.min(scroll.scrollLeft + dx * wheelPixelsPerUnit, scroll.scrollWidth - scroll.clientWidth)));
                e_preventDefault(e);
                display.wheelStartX = null; // Abort measurement, if in progress
                return;
            }

            if (dy && wheelPixelsPerUnit != null) {
                var pixels = dy * wheelPixelsPerUnit;
                var top = cm.doc.scrollTop, bot = top + display.wrapper.clientHeight;
                if (pixels < 0) top = Math.max(0, top + pixels - 50);
                else bot = Math.min(cm.doc.height, bot + pixels + 50);
                updateDisplay(cm, [], {top: top, bottom: bot});
            }

            if (wheelSamples < 20) {
                if (display.wheelStartX == null) {
                    display.wheelStartX = scroll.scrollLeft; display.wheelStartY = scroll.scrollTop;
                    display.wheelDX = dx; display.wheelDY = dy;
                    setTimeout(function() {
                        if (display.wheelStartX == null) return;
                        var movedX = scroll.scrollLeft - display.wheelStartX;
                        var movedY = scroll.scrollTop - display.wheelStartY;
                        var sample = (movedY && display.wheelDY && movedY / display.wheelDY) ||
                            (movedX && display.wheelDX && movedX / display.wheelDX);
                        display.wheelStartX = display.wheelStartY = null;
                        if (!sample) return;
                        wheelPixelsPerUnit = (wheelPixelsPerUnit * wheelSamples + sample) / (wheelSamples + 1);
                        ++wheelSamples;
                    }, 200);
                } else {
                    display.wheelDX += dx; display.wheelDY += dy;
                }
            }
        }

        function doHandleBinding(cm, bound, dropShift) {
            if (typeof bound == "string") {
                bound = commands[bound];
                if (!bound) return false;
            }
            // Ensure previous input has been read, so that the handler sees a
            // consistent view of the document
            if (cm.display.pollingFast && readInput(cm)) cm.display.pollingFast = false;
            var doc = cm.doc, prevShift = doc.sel.shift, done = false;
            try {
                if (isReadOnly(cm)) cm.state.suppressEdits = true;
                if (dropShift) doc.sel.shift = false;
                done = bound(cm) != Pass;
            } finally {
                doc.sel.shift = prevShift;
                cm.state.suppressEdits = false;
            }
            return done;
        }

        function allKeyMaps(cm) {
            var maps = cm.state.keyMaps.slice(0);
            if (cm.options.extraKeys) maps.push(cm.options.extraKeys);
            maps.push(cm.options.keyMap);
            return maps;
        }

        var maybeTransition;
        function handleKeyBinding(cm, e) {
            // Handle auto keymap transitions
            var startMap = getKeyMap(cm.options.keyMap), next = startMap.auto;
            clearTimeout(maybeTransition);
            if (next && !isModifierKey(e)) maybeTransition = setTimeout(function() {
                if (getKeyMap(cm.options.keyMap) == startMap) {
                    cm.options.keyMap = (next.call ? next.call(null, cm) : next);
                    keyMapChanged(cm);
                }
            }, 50);

            var name = keyName(e, true), handled = false;
            if (!name) return false;
            var keymaps = allKeyMaps(cm);

            if (e.shiftKey) {
                // First try to resolve full name (including 'Shift-'). Failing
                // that, see if there is a cursor-motion command (starting with
                // 'go') bound to the keyname without 'Shift-'.
                handled = lookupKey("Shift-" + name, keymaps, function(b) {return doHandleBinding(cm, b, true);})
                    || lookupKey(name, keymaps, function(b) {
                        if (typeof b == "string" ? /^go[A-Z]/.test(b) : b.motion)
                            return doHandleBinding(cm, b);
                    });
            } else {
                handled = lookupKey(name, keymaps, function(b) { return doHandleBinding(cm, b); });
            }

            if (handled) {
                e_preventDefault(e);
                restartBlink(cm);
                if (ie_lt9) { e.oldKeyCode = e.keyCode; e.keyCode = 0; }
                signalLater(cm, "keyHandled", cm, name, e);
            }
            return handled;
        }

        function handleCharBinding(cm, e, ch) {
            var handled = lookupKey("'" + ch + "'", allKeyMaps(cm),
                function(b) { return doHandleBinding(cm, b, true); });
            if (handled) {
                e_preventDefault(e);
                restartBlink(cm);
                signalLater(cm, "keyHandled", cm, "'" + ch + "'", e);
            }
            return handled;
        }

        var lastStoppedKey = null;
        function onKeyDown(e) {
            var cm = this;
            if (!cm.state.focused) onFocus(cm);
            if (ie && e.keyCode == 27) { e.returnValue = false; }
            if (signalDOMEvent(cm, e) || cm.options.onKeyEvent && cm.options.onKeyEvent(cm, addStop(e))) return;
            var code = e.keyCode;
            // IE does strange things with escape.
            cm.doc.sel.shift = code == 16 || e.shiftKey;
            // First give onKeyEvent option a chance to handle this.
            var handled = handleKeyBinding(cm, e);
            if (opera) {
                lastStoppedKey = handled ? code : null;
                // Opera has no cut event... we try to at least catch the key combo
                if (!handled && code == 88 && !hasCopyEvent && (mac ? e.metaKey : e.ctrlKey))
                    cm.replaceSelection("");
            }
        }

        function onKeyPress(e) {
            var cm = this;
            if (signalDOMEvent(cm, e) || cm.options.onKeyEvent && cm.options.onKeyEvent(cm, addStop(e))) return;
            var keyCode = e.keyCode, charCode = e.charCode;
            if (opera && keyCode == lastStoppedKey) {lastStoppedKey = null; e_preventDefault(e); return;}
            if (((opera && (!e.which || e.which < 10)) || khtml) && handleKeyBinding(cm, e)) return;
            var ch = String.fromCharCode(charCode == null ? keyCode : charCode);
            if (this.options.electricChars && this.doc.mode.electricChars &&
                this.options.smartIndent && !isReadOnly(this) &&
                this.doc.mode.electricChars.indexOf(ch) > -1)
                setTimeout(operation(cm, function() {indentLine(cm, cm.doc.sel.to.line, "smart");}), 75);
            if (handleCharBinding(cm, e, ch)) return;
            if (ie && !ie_lt9) cm.display.inputHasSelection = null;
            fastPoll(cm);
        }

        function onFocus(cm) {
            if (cm.options.readOnly == "nocursor") return;
            if (!cm.state.focused) {
                signal(cm, "focus", cm);
                cm.state.focused = true;
                if (cm.display.wrapper.className.search(/\bCodeMirror-focused\b/) == -1)
                    cm.display.wrapper.className += " CodeMirror-focused";
                resetInput(cm, true);
            }
            slowPoll(cm);
            restartBlink(cm);
        }
        function onBlur(cm) {
            if (cm.state.focused) {
                signal(cm, "blur", cm);
                cm.state.focused = false;
                cm.display.wrapper.className = cm.display.wrapper.className.replace(" CodeMirror-focused", "");
            }
            clearInterval(cm.display.blinker);
            setTimeout(function() {if (!cm.state.focused) cm.doc.sel.shift = false;}, 150);
        }

        var detectingSelectAll;
        function onContextMenu(cm, e) {
            if (signalDOMEvent(cm, e, "contextmenu")) return;
            var display = cm.display, sel = cm.doc.sel;
            if (eventInWidget(display, e)) return;

            var pos = posFromMouse(cm, e), scrollPos = display.scroller.scrollTop;
            if (!pos || opera) return; // Opera is difficult.
            if (posEq(sel.from, sel.to) || posLess(pos, sel.from) || !posLess(pos, sel.to))
                operation(cm, setSelection)(cm.doc, pos, pos);

            var oldCSS = display.input.style.cssText;
            display.inputDiv.style.position = "absolute";
            display.input.style.cssText = "position: fixed; width: 30px; height: 30px; top: " + (e.clientY - 5) +
                "px; left: " + (e.clientX - 5) + "px; z-index: 1000; background: white; outline: none;" +
                "border-width: 0; outline: none; overflow: hidden; opacity: .05; -ms-opacity: .05; filter: alpha(opacity=5);";
            focusInput(cm);
            resetInput(cm, true);
            // Adds "Select all" to context menu in FF
            if (posEq(sel.from, sel.to)) display.input.value = display.prevInput = " ";

            function prepareSelectAllHack() {
                if (display.input.selectionStart != null) {
                    var extval = display.input.value = " " + (posEq(sel.from, sel.to) ? "" : display.input.value);
                    display.prevInput = " ";
                    display.input.selectionStart = 1; display.input.selectionEnd = extval.length;
                }
            }
            function rehide() {
                display.inputDiv.style.position = "relative";
                display.input.style.cssText = oldCSS;
                if (ie_lt9) display.scrollbarV.scrollTop = display.scroller.scrollTop = scrollPos;
                slowPoll(cm);

                // Try to detect the user choosing select-all
                if (display.input.selectionStart != null) {
                    if (!ie || ie_lt9) prepareSelectAllHack();
                    clearTimeout(detectingSelectAll);
                    var i = 0, poll = function(){
                        if (display.prevInput == " " && display.input.selectionStart == 0)
                            operation(cm, commands.selectAll)(cm);
                        else if (i++ < 10) detectingSelectAll = setTimeout(poll, 500);
                        else resetInput(cm);
                    };
                    detectingSelectAll = setTimeout(poll, 200);
                }
            }

            if (ie && !ie_lt9) prepareSelectAllHack();
            if (captureMiddleClick) {
                e_stop(e);
                var mouseup = function() {
                    off(window, "mouseup", mouseup);
                    setTimeout(rehide, 20);
                };
                on(window, "mouseup", mouseup);
            } else {
                setTimeout(rehide, 50);
            }
        }

        // UPDATING

        var changeEnd = CodeMirror.changeEnd = function(change) {
            if (!change.text) return change.to;
            return Pos(change.from.line + change.text.length - 1,
                    lst(change.text).length + (change.text.length == 1 ? change.from.ch : 0));
        };

        // Make sure a position will be valid after the given change.
        function clipPostChange(doc, change, pos) {
            if (!posLess(change.from, pos)) return clipPos(doc, pos);
            var diff = (change.text.length - 1) - (change.to.line - change.from.line);
            if (pos.line > change.to.line + diff) {
                var preLine = pos.line - diff, lastLine = doc.first + doc.size - 1;
                if (preLine > lastLine) return Pos(lastLine, getLine(doc, lastLine).text.length);
                return clipToLen(pos, getLine(doc, preLine).text.length);
            }
            if (pos.line == change.to.line + diff)
                return clipToLen(pos, lst(change.text).length + (change.text.length == 1 ? change.from.ch : 0) +
                    getLine(doc, change.to.line).text.length - change.to.ch);
            var inside = pos.line - change.from.line;
            return clipToLen(pos, change.text[inside].length + (inside ? 0 : change.from.ch));
        }

        // Hint can be null|"end"|"start"|"around"|{anchor,head}
        function computeSelAfterChange(doc, change, hint) {
            if (hint && typeof hint == "object") // Assumed to be {anchor, head} object
                return {anchor: clipPostChange(doc, change, hint.anchor),
                    head: clipPostChange(doc, change, hint.head)};

            if (hint == "start") return {anchor: change.from, head: change.from};

            var end = changeEnd(change);
            if (hint == "around") return {anchor: change.from, head: end};
            if (hint == "end") return {anchor: end, head: end};

            // hint is null, leave the selection alone as much as possible
            var adjustPos = function(pos) {
                if (posLess(pos, change.from)) return pos;
                if (!posLess(change.to, pos)) return end;

                var line = pos.line + change.text.length - (change.to.line - change.from.line) - 1, ch = pos.ch;
                if (pos.line == change.to.line) ch += end.ch - change.to.ch;
                return Pos(line, ch);
            };
            return {anchor: adjustPos(doc.sel.anchor), head: adjustPos(doc.sel.head)};
        }

        function filterChange(doc, change, update) {
            var obj = {
                canceled: false,
                from: change.from,
                to: change.to,
                text: change.text,
                origin: change.origin,
                cancel: function() { this.canceled = true; }
            };
            if (update) obj.update = function(from, to, text, origin) {
                if (from) this.from = clipPos(doc, from);
                if (to) this.to = clipPos(doc, to);
                if (text) this.text = text;
                if (origin !== undefined) this.origin = origin;
            };
            signal(doc, "beforeChange", doc, obj);
            if (doc.cm) signal(doc.cm, "beforeChange", doc.cm, obj);

            if (obj.canceled) return null;
            return {from: obj.from, to: obj.to, text: obj.text, origin: obj.origin};
        }

        // Replace the range from from to to by the strings in replacement.
        // change is a {from, to, text [, origin]} object
        function makeChange(doc, change, selUpdate, ignoreReadOnly) {
            if (doc.cm) {
                if (!doc.cm.curOp) return operation(doc.cm, makeChange)(doc, change, selUpdate, ignoreReadOnly);
                if (doc.cm.state.suppressEdits) return;
            }

            if (hasHandler(doc, "beforeChange") || doc.cm && hasHandler(doc.cm, "beforeChange")) {
                change = filterChange(doc, change, true);
                if (!change) return;
            }

            // Possibly split or suppress the update based on the presence
            // of read-only spans in its range.
            var split = sawReadOnlySpans && !ignoreReadOnly && removeReadOnlyRanges(doc, change.from, change.to);
            if (split) {
                for (var i = split.length - 1; i >= 1; --i)
                    makeChangeNoReadonly(doc, {from: split[i].from, to: split[i].to, text: [""]});
                if (split.length)
                    makeChangeNoReadonly(doc, {from: split[0].from, to: split[0].to, text: change.text}, selUpdate);
            } else {
                makeChangeNoReadonly(doc, change, selUpdate);
            }
        }

        function makeChangeNoReadonly(doc, change, selUpdate) {
            var selAfter = computeSelAfterChange(doc, change, selUpdate);
            addToHistory(doc, change, selAfter, doc.cm ? doc.cm.curOp.id : NaN);

            makeChangeSingleDoc(doc, change, selAfter, stretchSpansOverChange(doc, change));
            var rebased = [];

            linkedDocs(doc, function(doc, sharedHist) {
                if (!sharedHist && indexOf(rebased, doc.history) == -1) {
                    rebaseHist(doc.history, change);
                    rebased.push(doc.history);
                }
                makeChangeSingleDoc(doc, change, null, stretchSpansOverChange(doc, change));
            });
        }

        function makeChangeFromHistory(doc, type) {
            if (doc.cm && doc.cm.state.suppressEdits) return;

            var hist = doc.history;
            var event = (type == "undo" ? hist.done : hist.undone).pop();
            if (!event) return;

            var anti = {changes: [], anchorBefore: event.anchorAfter, headBefore: event.headAfter,
                anchorAfter: event.anchorBefore, headAfter: event.headBefore,
                generation: hist.generation};
            (type == "undo" ? hist.undone : hist.done).push(anti);
            hist.generation = event.generation || ++hist.maxGeneration;

            var filter = hasHandler(doc, "beforeChange") || doc.cm && hasHandler(doc.cm, "beforeChange");

            for (var i = event.changes.length - 1; i >= 0; --i) {
                var change = event.changes[i];
                change.origin = type;
                if (filter && !filterChange(doc, change, false)) {
                    (type == "undo" ? hist.done : hist.undone).length = 0;
                    return;
                }

                anti.changes.push(historyChangeFromChange(doc, change));

                var after = i ? computeSelAfterChange(doc, change, null)
                    : {anchor: event.anchorBefore, head: event.headBefore};
                makeChangeSingleDoc(doc, change, after, mergeOldSpans(doc, change));
                var rebased = [];

                linkedDocs(doc, function(doc, sharedHist) {
                    if (!sharedHist && indexOf(rebased, doc.history) == -1) {
                        rebaseHist(doc.history, change);
                        rebased.push(doc.history);
                    }
                    makeChangeSingleDoc(doc, change, null, mergeOldSpans(doc, change));
                });
            }
        }

        function shiftDoc(doc, distance) {
            function shiftPos(pos) {return Pos(pos.line + distance, pos.ch);}
            doc.first += distance;
            if (doc.cm) regChange(doc.cm, doc.first, doc.first, distance);
            doc.sel.head = shiftPos(doc.sel.head); doc.sel.anchor = shiftPos(doc.sel.anchor);
            doc.sel.from = shiftPos(doc.sel.from); doc.sel.to = shiftPos(doc.sel.to);
        }

        function makeChangeSingleDoc(doc, change, selAfter, spans) {
            if (doc.cm && !doc.cm.curOp)
                return operation(doc.cm, makeChangeSingleDoc)(doc, change, selAfter, spans);

            if (change.to.line < doc.first) {
                shiftDoc(doc, change.text.length - 1 - (change.to.line - change.from.line));
                return;
            }
            if (change.from.line > doc.lastLine()) return;

            // Clip the change to the size of this doc
            if (change.from.line < doc.first) {
                var shift = change.text.length - 1 - (doc.first - change.from.line);
                shiftDoc(doc, shift);
                change = {from: Pos(doc.first, 0), to: Pos(change.to.line + shift, change.to.ch),
                    text: [lst(change.text)], origin: change.origin};
            }
            var last = doc.lastLine();
            if (change.to.line > last) {
                change = {from: change.from, to: Pos(last, getLine(doc, last).text.length),
                    text: [change.text[0]], origin: change.origin};
            }

            change.removed = getBetween(doc, change.from, change.to);

            if (!selAfter) selAfter = computeSelAfterChange(doc, change, null);
            if (doc.cm) makeChangeSingleDocInEditor(doc.cm, change, spans, selAfter);
            else updateDoc(doc, change, spans, selAfter);
        }

        function makeChangeSingleDocInEditor(cm, change, spans, selAfter) {
            var doc = cm.doc, display = cm.display, from = change.from, to = change.to;

            var recomputeMaxLength = false, checkWidthStart = from.line;
            if (!cm.options.lineWrapping) {
                checkWidthStart = lineNo(visualLine(doc, getLine(doc, from.line)));
                doc.iter(checkWidthStart, to.line + 1, function(line) {
                    if (line == display.maxLine) {
                        recomputeMaxLength = true;
                        return true;
                    }
                });
            }

            if (!posLess(doc.sel.head, change.from) && !posLess(change.to, doc.sel.head))
                cm.curOp.cursorActivity = true;

            updateDoc(doc, change, spans, selAfter, estimateHeight(cm));

            if (!cm.options.lineWrapping) {
                doc.iter(checkWidthStart, from.line + change.text.length, function(line) {
                    var len = lineLength(doc, line);
                    if (len > display.maxLineLength) {
                        display.maxLine = line;
                        display.maxLineLength = len;
                        display.maxLineChanged = true;
                        recomputeMaxLength = false;
                    }
                });
                if (recomputeMaxLength) cm.curOp.updateMaxLine = true;
            }

            // Adjust frontier, schedule worker
            doc.frontier = Math.min(doc.frontier, from.line);
            startWorker(cm, 400);

            var lendiff = change.text.length - (to.line - from.line) - 1;
            // Remember that these lines changed, for updating the display
            regChange(cm, from.line, to.line + 1, lendiff);

            if (hasHandler(cm, "change")) {
                var changeObj = {from: from, to: to,
                    text: change.text,
                    removed: change.removed,
                    origin: change.origin};
                if (cm.curOp.textChanged) {
                    for (var cur = cm.curOp.textChanged; cur.next; cur = cur.next) {}
                    cur.next = changeObj;
                } else cm.curOp.textChanged = changeObj;
            }
        }

        function replaceRange(doc, code, from, to, origin) {
            if (!to) to = from;
            if (posLess(to, from)) { var tmp = to; to = from; from = tmp; }
            if (typeof code == "string") code = splitLines(code);
            makeChange(doc, {from: from, to: to, text: code, origin: origin}, null);
        }

        // POSITION OBJECT

        function Pos(line, ch) {
            if (!(this instanceof Pos)) return new Pos(line, ch);
            this.line = line; this.ch = ch;
        }
        CodeMirror.Pos = Pos;

        function posEq(a, b) {return a.line == b.line && a.ch == b.ch;}
        function posLess(a, b) {return a.line < b.line || (a.line == b.line && a.ch < b.ch);}
        function copyPos(x) {return Pos(x.line, x.ch);}

        // SELECTION

        function clipLine(doc, n) {return Math.max(doc.first, Math.min(n, doc.first + doc.size - 1));}
        function clipPos(doc, pos) {
            if (pos.line < doc.first) return Pos(doc.first, 0);
            var last = doc.first + doc.size - 1;
            if (pos.line > last) return Pos(last, getLine(doc, last).text.length);
            return clipToLen(pos, getLine(doc, pos.line).text.length);
        }
        function clipToLen(pos, linelen) {
            var ch = pos.ch;
            if (ch == null || ch > linelen) return Pos(pos.line, linelen);
            else if (ch < 0) return Pos(pos.line, 0);
            else return pos;
        }
        function isLine(doc, l) {return l >= doc.first && l < doc.first + doc.size;}

        // If shift is held, this will move the selection anchor. Otherwise,
        // it'll set the whole selection.
        function extendSelection(doc, pos, other, bias) {
            if (doc.sel.shift || doc.sel.extend) {
                var anchor = doc.sel.anchor;
                if (other) {
                    var posBefore = posLess(pos, anchor);
                    if (posBefore != posLess(other, anchor)) {
                        anchor = pos;
                        pos = other;
                    } else if (posBefore != posLess(pos, other)) {
                        pos = other;
                    }
                }
                setSelection(doc, anchor, pos, bias);
            } else {
                setSelection(doc, pos, other || pos, bias);
            }
            if (doc.cm) doc.cm.curOp.userSelChange = true;
        }

        function filterSelectionChange(doc, anchor, head) {
            var obj = {anchor: anchor, head: head};
            signal(doc, "beforeSelectionChange", doc, obj);
            if (doc.cm) signal(doc.cm, "beforeSelectionChange", doc.cm, obj);
            obj.anchor = clipPos(doc, obj.anchor); obj.head = clipPos(doc, obj.head);
            return obj;
        }

        // Update the selection. Last two args are only used by
        // updateDoc, since they have to be expressed in the line
        // numbers before the update.
        function setSelection(doc, anchor, head, bias, checkAtomic) {
            if (!checkAtomic && hasHandler(doc, "beforeSelectionChange") || doc.cm && hasHandler(doc.cm, "beforeSelectionChange")) {
                var filtered = filterSelectionChange(doc, anchor, head);
                head = filtered.head;
                anchor = filtered.anchor;
            }

            var sel = doc.sel;
            sel.goalColumn = null;
            // Skip over atomic spans.
            if (checkAtomic || !posEq(anchor, sel.anchor))
                anchor = skipAtomic(doc, anchor, bias, checkAtomic != "push");
            if (checkAtomic || !posEq(head, sel.head))
                head = skipAtomic(doc, head, bias, checkAtomic != "push");

            if (posEq(sel.anchor, anchor) && posEq(sel.head, head)) return;

            sel.anchor = anchor; sel.head = head;
            var inv = posLess(head, anchor);
            sel.from = inv ? head : anchor;
            sel.to = inv ? anchor : head;

            if (doc.cm)
                doc.cm.curOp.updateInput = doc.cm.curOp.selectionChanged =
                    doc.cm.curOp.cursorActivity = true;

            signalLater(doc, "cursorActivity", doc);
        }

        function reCheckSelection(cm) {
            setSelection(cm.doc, cm.doc.sel.from, cm.doc.sel.to, null, "push");
        }

        function skipAtomic(doc, pos, bias, mayClear) {
            var flipped = false, curPos = pos;
            var dir = bias || 1;
            doc.cantEdit = false;
            search: for (;;) {
                var line = getLine(doc, curPos.line);
                if (line.markedSpans) {
                    for (var i = 0; i < line.markedSpans.length; ++i) {
                        var sp = line.markedSpans[i], m = sp.marker;
                        if ((sp.from == null || (m.inclusiveLeft ? sp.from <= curPos.ch : sp.from < curPos.ch)) &&
                            (sp.to == null || (m.inclusiveRight ? sp.to >= curPos.ch : sp.to > curPos.ch))) {
                            if (mayClear) {
                                signal(m, "beforeCursorEnter");
                                if (m.explicitlyCleared) {
                                    if (!line.markedSpans) break;
                                    else {--i; continue;}
                                }
                            }
                            if (!m.atomic) continue;
                            var newPos = m.find()[dir < 0 ? "from" : "to"];
                            if (posEq(newPos, curPos)) {
                                newPos.ch += dir;
                                if (newPos.ch < 0) {
                                    if (newPos.line > doc.first) newPos = clipPos(doc, Pos(newPos.line - 1));
                                    else newPos = null;
                                } else if (newPos.ch > line.text.length) {
                                    if (newPos.line < doc.first + doc.size - 1) newPos = Pos(newPos.line + 1, 0);
                                    else newPos = null;
                                }
                                if (!newPos) {
                                    if (flipped) {
                                        // Driven in a corner -- no valid cursor position found at all
                                        // -- try again *with* clearing, if we didn't already
                                        if (!mayClear) return skipAtomic(doc, pos, bias, true);
                                        // Otherwise, turn off editing until further notice, and return the start of the doc
                                        doc.cantEdit = true;
                                        return Pos(doc.first, 0);
                                    }
                                    flipped = true; newPos = pos; dir = -dir;
                                }
                            }
                            curPos = newPos;
                            continue search;
                        }
                    }
                }
                return curPos;
            }
        }

        // SCROLLING

        function scrollCursorIntoView(cm) {
            var coords = scrollPosIntoView(cm, cm.doc.sel.head, cm.options.cursorScrollMargin);
            if (!cm.state.focused) return;
            var display = cm.display, box = getRect(display.sizer), doScroll = null;
            if (coords.top + box.top < 0) doScroll = true;
            else if (coords.bottom + box.top > (window.innerHeight || document.documentElement.clientHeight)) doScroll = false;
            if (doScroll != null && !phantom) {
                var hidden = display.cursor.style.display == "none";
                if (hidden) {
                    display.cursor.style.display = "";
                    display.cursor.style.left = coords.left + "px";
                    display.cursor.style.top = (coords.top - display.viewOffset) + "px";
                }
                display.cursor.scrollIntoView(doScroll);
                if (hidden) display.cursor.style.display = "none";
            }
        }

        function scrollPosIntoView(cm, pos, margin) {
            if (margin == null) margin = 0;
            for (;;) {
                var changed = false, coords = cursorCoords(cm, pos);
                var scrollPos = calculateScrollPos(cm, coords.left, coords.top - margin, coords.left, coords.bottom + margin);
                var startTop = cm.doc.scrollTop, startLeft = cm.doc.scrollLeft;
                if (scrollPos.scrollTop != null) {
                    setScrollTop(cm, scrollPos.scrollTop);
                    if (Math.abs(cm.doc.scrollTop - startTop) > 1) changed = true;
                }
                if (scrollPos.scrollLeft != null) {
                    setScrollLeft(cm, scrollPos.scrollLeft);
                    if (Math.abs(cm.doc.scrollLeft - startLeft) > 1) changed = true;
                }
                if (!changed) return coords;
            }
        }

        function scrollIntoView(cm, x1, y1, x2, y2) {
            var scrollPos = calculateScrollPos(cm, x1, y1, x2, y2);
            if (scrollPos.scrollTop != null) setScrollTop(cm, scrollPos.scrollTop);
            if (scrollPos.scrollLeft != null) setScrollLeft(cm, scrollPos.scrollLeft);
        }

        function calculateScrollPos(cm, x1, y1, x2, y2) {
            var display = cm.display, snapMargin = textHeight(cm.display);
            if (y1 < 0) y1 = 0;
            var screen = display.scroller.clientHeight - scrollerCutOff, screentop = display.scroller.scrollTop, result = {};
            var docBottom = cm.doc.height + paddingVert(display);
            var atTop = y1 < snapMargin, atBottom = y2 > docBottom - snapMargin;
            if (y1 < screentop) {
                result.scrollTop = atTop ? 0 : y1;
            } else if (y2 > screentop + screen) {
                var newTop = Math.min(y1, (atBottom ? docBottom : y2) - screen);
                if (newTop != screentop) result.scrollTop = newTop;
            }

            var screenw = display.scroller.clientWidth - scrollerCutOff, screenleft = display.scroller.scrollLeft;
            x1 += display.gutters.offsetWidth; x2 += display.gutters.offsetWidth;
            var gutterw = display.gutters.offsetWidth;
            var atLeft = x1 < gutterw + 10;
            if (x1 < screenleft + gutterw || atLeft) {
                if (atLeft) x1 = 0;
                result.scrollLeft = Math.max(0, x1 - 10 - gutterw);
            } else if (x2 > screenw + screenleft - 3) {
                result.scrollLeft = x2 + 10 - screenw;
            }
            return result;
        }

        function updateScrollPos(cm, left, top) {
            cm.curOp.updateScrollPos = {scrollLeft: left == null ? cm.doc.scrollLeft : left,
                scrollTop: top == null ? cm.doc.scrollTop : top};
        }

        function addToScrollPos(cm, left, top) {
            var pos = cm.curOp.updateScrollPos || (cm.curOp.updateScrollPos = {scrollLeft: cm.doc.scrollLeft, scrollTop: cm.doc.scrollTop});
            var scroll = cm.display.scroller;
            pos.scrollTop = Math.max(0, Math.min(scroll.scrollHeight - scroll.clientHeight, pos.scrollTop + top));
            pos.scrollLeft = Math.max(0, Math.min(scroll.scrollWidth - scroll.clientWidth, pos.scrollLeft + left));
        }

        // API UTILITIES

        function indentLine(cm, n, how, aggressive) {
            var doc = cm.doc;
            if (how == null) how = "add";
            if (how == "smart") {
                if (!cm.doc.mode.indent) how = "prev";
                else var state = getStateBefore(cm, n);
            }

            var tabSize = cm.options.tabSize;
            var line = getLine(doc, n), curSpace = countColumn(line.text, null, tabSize);
            var curSpaceString = line.text.match(/^\s*/)[0], indentation;
            if (how == "smart") {
                indentation = cm.doc.mode.indent(state, line.text.slice(curSpaceString.length), line.text);
                if (indentation == Pass) {
                    if (!aggressive) return;
                    how = "prev";
                }
            }
            if (how == "prev") {
                if (n > doc.first) indentation = countColumn(getLine(doc, n-1).text, null, tabSize);
                else indentation = 0;
            } else if (how == "add") {
                indentation = curSpace + cm.options.indentUnit;
            } else if (how == "subtract") {
                indentation = curSpace - cm.options.indentUnit;
            } else if (typeof how == "number") {
                indentation = curSpace + how;
            }
            indentation = Math.max(0, indentation);

            var indentString = "", pos = 0;
            if (cm.options.indentWithTabs)
                for (var i = Math.floor(indentation / tabSize); i; --i) {pos += tabSize; indentString += "\t";}
            if (pos < indentation) indentString += spaceStr(indentation - pos);

            if (indentString != curSpaceString)
                replaceRange(cm.doc, indentString, Pos(n, 0), Pos(n, curSpaceString.length), "+input");
            line.stateAfter = null;
        }

        function changeLine(cm, handle, op) {
            var no = handle, line = handle, doc = cm.doc;
            if (typeof handle == "number") line = getLine(doc, clipLine(doc, handle));
            else no = lineNo(handle);
            if (no == null) return null;
            if (op(line, no)) regChange(cm, no, no + 1);
            else return null;
            return line;
        }

        function findPosH(doc, pos, dir, unit, visually) {
            var line = pos.line, ch = pos.ch, origDir = dir;
            var lineObj = getLine(doc, line);
            var possible = true;
            function findNextLine() {
                var l = line + dir;
                if (l < doc.first || l >= doc.first + doc.size) return (possible = false);
                line = l;
                return lineObj = getLine(doc, l);
            }
            function moveOnce(boundToLine) {
                var next = (visually ? moveVisually : moveLogically)(lineObj, ch, dir, true);
                if (next == null) {
                    if (!boundToLine && findNextLine()) {
                        if (visually) ch = (dir < 0 ? lineRight : lineLeft)(lineObj);
                        else ch = dir < 0 ? lineObj.text.length : 0;
                    } else return (possible = false);
                } else ch = next;
                return true;
            }

            if (unit == "char") moveOnce();
            else if (unit == "column") moveOnce(true);
            else if (unit == "word" || unit == "group") {
                var sawType = null, group = unit == "group";
                for (var first = true;; first = false) {
                    if (dir < 0 && !moveOnce(!first)) break;
                    var cur = lineObj.text.charAt(ch) || "\n";
                    var type = isWordChar(cur) ? "w"
                        : !group ? null
                        : /\s/.test(cur) ? null
                        : "p";
                    if (sawType && sawType != type) {
                        if (dir < 0) {dir = 1; moveOnce();}
                        break;
                    }
                    if (type) sawType = type;
                    if (dir > 0 && !moveOnce(!first)) break;
                }
            }
            var result = skipAtomic(doc, Pos(line, ch), origDir, true);
            if (!possible) result.hitSide = true;
            return result;
        }

        function findPosV(cm, pos, dir, unit) {
            var doc = cm.doc, x = pos.left, y;
            if (unit == "page") {
                var pageSize = Math.min(cm.display.wrapper.clientHeight, window.innerHeight || document.documentElement.clientHeight);
                y = pos.top + dir * (pageSize - (dir < 0 ? 1.5 : .5) * textHeight(cm.display));
            } else if (unit == "line") {
                y = dir > 0 ? pos.bottom + 3 : pos.top - 3;
            }
            for (;;) {
                var target = coordsChar(cm, x, y);
                if (!target.outside) break;
                if (dir < 0 ? y <= 0 : y >= doc.height) { target.hitSide = true; break; }
                y += dir * 5;
            }
            return target;
        }

        function findWordAt(line, pos) {
            var start = pos.ch, end = pos.ch;
            if (line) {
                if ((pos.xRel < 0 || end == line.length) && start) --start; else ++end;
                var startChar = line.charAt(start);
                var check = isWordChar(startChar) ? isWordChar
                    : /\s/.test(startChar) ? function(ch) {return /\s/.test(ch);}
                    : function(ch) {return !/\s/.test(ch) && !isWordChar(ch);};
                while (start > 0 && check(line.charAt(start - 1))) --start;
                while (end < line.length && check(line.charAt(end))) ++end;
            }
            return {from: Pos(pos.line, start), to: Pos(pos.line, end)};
        }

        function selectLine(cm, line) {
            extendSelection(cm.doc, Pos(line, 0), clipPos(cm.doc, Pos(line + 1, 0)));
        }

        // PROTOTYPE

        // The publicly visible API. Note that operation(null, f) means
        // 'wrap f in an operation, performed on its `this` parameter'

        CodeMirror.prototype = {
            constructor: CodeMirror,
            focus: function(){window.focus(); focusInput(this); onFocus(this); fastPoll(this);},

            setOption: function(option, value) {
                var options = this.options, old = options[option];
                if (options[option] == value && option != "mode") return;
                options[option] = value;
                if (optionHandlers.hasOwnProperty(option))
                    operation(this, optionHandlers[option])(this, value, old);
            },

            getOption: function(option) {return this.options[option];},
            getDoc: function() {return this.doc;},

            addKeyMap: function(map, bottom) {
                this.state.keyMaps[bottom ? "push" : "unshift"](map);
            },
            removeKeyMap: function(map) {
                var maps = this.state.keyMaps;
                for (var i = 0; i < maps.length; ++i)
                    if (maps[i] == map || (typeof maps[i] != "string" && maps[i].name == map)) {
                        maps.splice(i, 1);
                        return true;
                    }
            },

            addOverlay: operation(null, function(spec, options) {
                var mode = spec.token ? spec : CodeMirror.getMode(this.options, spec);
                if (mode.startState) throw new Error("Overlays may not be stateful.");
                this.state.overlays.push({mode: mode, modeSpec: spec, opaque: options && options.opaque});
                this.state.modeGen++;
                regChange(this);
            }),
            removeOverlay: operation(null, function(spec) {
                var overlays = this.state.overlays;
                for (var i = 0; i < overlays.length; ++i) {
                    var cur = overlays[i].modeSpec;
                    if (cur == spec || typeof spec == "string" && cur.name == spec) {
                        overlays.splice(i, 1);
                        this.state.modeGen++;
                        regChange(this);
                        return;
                    }
                }
            }),

            indentLine: operation(null, function(n, dir, aggressive) {
                if (typeof dir != "string" && typeof dir != "number") {
                    if (dir == null) dir = this.options.smartIndent ? "smart" : "prev";
                    else dir = dir ? "add" : "subtract";
                }
                if (isLine(this.doc, n)) indentLine(this, n, dir, aggressive);
            }),
            indentSelection: operation(null, function(how) {
                var sel = this.doc.sel;
                if (posEq(sel.from, sel.to)) return indentLine(this, sel.from.line, how);
                var e = sel.to.line - (sel.to.ch ? 0 : 1);
                for (var i = sel.from.line; i <= e; ++i) indentLine(this, i, how);
            }),

            // Fetch the parser token for a given character. Useful for hacks
            // that want to inspect the mode state (say, for completion).
            getTokenAt: function(pos, precise) {
                var doc = this.doc;
                pos = clipPos(doc, pos);
                var state = getStateBefore(this, pos.line, precise), mode = this.doc.mode;
                var line = getLine(doc, pos.line);
                var stream = new StringStream(line.text, this.options.tabSize);
                while (stream.pos < pos.ch && !stream.eol()) {
                    stream.start = stream.pos;
                    var style = mode.token(stream, state);
                }
                return {start: stream.start,
                    end: stream.pos,
                    string: stream.current(),
                    className: style || null, // Deprecated, use 'type' instead
                    type: style || null,
                    state: state};
            },

            getTokenTypeAt: function(pos) {
                pos = clipPos(this.doc, pos);
                var styles = getLineStyles(this, getLine(this.doc, pos.line));
                var before = 0, after = (styles.length - 1) / 2, ch = pos.ch;
                if (ch == 0) return styles[2];
                for (;;) {
                    var mid = (before + after) >> 1;
                    if ((mid ? styles[mid * 2 - 1] : 0) >= ch) after = mid;
                    else if (styles[mid * 2 + 1] < ch) before = mid + 1;
                    else return styles[mid * 2 + 2];
                }
            },

            getModeAt: function(pos) {
                var mode = this.doc.mode;
                if (!mode.innerMode) return mode;
                return CodeMirror.innerMode(mode, this.getTokenAt(pos).state).mode;
            },

            getHelper: function(pos, type) {
                if (!helpers.hasOwnProperty(type)) return;
                var help = helpers[type], mode = this.getModeAt(pos);
                return mode[type] && help[mode[type]] ||
                    mode.helperType && help[mode.helperType] ||
                    help[mode.name];
            },

            getStateAfter: function(line, precise) {
                var doc = this.doc;
                line = clipLine(doc, line == null ? doc.first + doc.size - 1: line);
                return getStateBefore(this, line + 1, precise);
            },

            cursorCoords: function(start, mode) {
                var pos, sel = this.doc.sel;
                if (start == null) pos = sel.head;
                else if (typeof start == "object") pos = clipPos(this.doc, start);
                else pos = start ? sel.from : sel.to;
                return cursorCoords(this, pos, mode || "page");
            },

            charCoords: function(pos, mode) {
                return charCoords(this, clipPos(this.doc, pos), mode || "page");
            },

            coordsChar: function(coords, mode) {
                coords = fromCoordSystem(this, coords, mode || "page");
                return coordsChar(this, coords.left, coords.top);
            },

            lineAtHeight: function(height, mode) {
                height = fromCoordSystem(this, {top: height, left: 0}, mode || "page").top;
                return lineAtHeight(this.doc, height + this.display.viewOffset);
            },
            heightAtLine: function(line, mode) {
                var end = false, last = this.doc.first + this.doc.size - 1;
                if (line < this.doc.first) line = this.doc.first;
                else if (line > last) { line = last; end = true; }
                var lineObj = getLine(this.doc, line);
                return intoCoordSystem(this, getLine(this.doc, line), {top: 0, left: 0}, mode || "page").top +
                    (end ? lineObj.height : 0);
            },

            defaultTextHeight: function() { return textHeight(this.display); },
            defaultCharWidth: function() { return charWidth(this.display); },

            setGutterMarker: operation(null, function(line, gutterID, value) {
                return changeLine(this, line, function(line) {
                    var markers = line.gutterMarkers || (line.gutterMarkers = {});
                    markers[gutterID] = value;
                    if (!value && isEmpty(markers)) line.gutterMarkers = null;
                    return true;
                });
            }),

            clearGutter: operation(null, function(gutterID) {
                var cm = this, doc = cm.doc, i = doc.first;
                doc.iter(function(line) {
                    if (line.gutterMarkers && line.gutterMarkers[gutterID]) {
                        line.gutterMarkers[gutterID] = null;
                        regChange(cm, i, i + 1);
                        if (isEmpty(line.gutterMarkers)) line.gutterMarkers = null;
                    }
                    ++i;
                });
            }),

            addLineClass: operation(null, function(handle, where, cls) {
                return changeLine(this, handle, function(line) {
                    var prop = where == "text" ? "textClass" : where == "background" ? "bgClass" : "wrapClass";
                    if (!line[prop]) line[prop] = cls;
                    else if (new RegExp("(?:^|\\s)" + cls + "(?:$|\\s)").test(line[prop])) return false;
                    else line[prop] += " " + cls;
                    return true;
                });
            }),

            removeLineClass: operation(null, function(handle, where, cls) {
                return changeLine(this, handle, function(line) {
                    var prop = where == "text" ? "textClass" : where == "background" ? "bgClass" : "wrapClass";
                    var cur = line[prop];
                    if (!cur) return false;
                    else if (cls == null) line[prop] = null;
                    else {
                        var found = cur.match(new RegExp("(?:^|\\s+)" + cls + "(?:$|\\s+)"));
                        if (!found) return false;
                        var end = found.index + found[0].length;
                        line[prop] = cur.slice(0, found.index) + (!found.index || end == cur.length ? "" : " ") + cur.slice(end) || null;
                    }
                    return true;
                });
            }),

            addLineWidget: operation(null, function(handle, node, options) {
                return addLineWidget(this, handle, node, options);
            }),

            removeLineWidget: function(widget) { widget.clear(); },

            lineInfo: function(line) {
                if (typeof line == "number") {
                    if (!isLine(this.doc, line)) return null;
                    var n = line;
                    line = getLine(this.doc, line);
                    if (!line) return null;
                } else {
                    var n = lineNo(line);
                    if (n == null) return null;
                }
                return {line: n, handle: line, text: line.text, gutterMarkers: line.gutterMarkers,
                    textClass: line.textClass, bgClass: line.bgClass, wrapClass: line.wrapClass,
                    widgets: line.widgets};
            },

            getViewport: function() { return {from: this.display.showingFrom, to: this.display.showingTo};},

            addWidget: function(pos, node, scroll, vert, horiz) {
                var display = this.display;
                pos = cursorCoords(this, clipPos(this.doc, pos));
                var top = pos.bottom, left = pos.left;
                node.style.position = "absolute";
                display.sizer.appendChild(node);
                if (vert == "over") {
                    top = pos.top;
                } else if (vert == "above" || vert == "near") {
                    var vspace = Math.max(display.wrapper.clientHeight, this.doc.height),
                        hspace = Math.max(display.sizer.clientWidth, display.lineSpace.clientWidth);
                    // Default to positioning above (if specified and possible); otherwise default to positioning below
                    if ((vert == 'above' || pos.bottom + node.offsetHeight > vspace) && pos.top > node.offsetHeight)
                        top = pos.top - node.offsetHeight;
                    else if (pos.bottom + node.offsetHeight <= vspace)
                        top = pos.bottom;
                    if (left + node.offsetWidth > hspace)
                        left = hspace - node.offsetWidth;
                }
                node.style.top = top + "px";
                node.style.left = node.style.right = "";
                if (horiz == "right") {
                    left = display.sizer.clientWidth - node.offsetWidth;
                    node.style.right = "0px";
                } else {
                    if (horiz == "left") left = 0;
                    else if (horiz == "middle") left = (display.sizer.clientWidth - node.offsetWidth) / 2;
                    node.style.left = left + "px";
                }
                if (scroll)
                    scrollIntoView(this, left, top, left + node.offsetWidth, top + node.offsetHeight);
            },

            triggerOnKeyDown: operation(null, onKeyDown),

            execCommand: function(cmd) {return commands[cmd](this);},

            findPosH: function(from, amount, unit, visually) {
                var dir = 1;
                if (amount < 0) { dir = -1; amount = -amount; }
                for (var i = 0, cur = clipPos(this.doc, from); i < amount; ++i) {
                    cur = findPosH(this.doc, cur, dir, unit, visually);
                    if (cur.hitSide) break;
                }
                return cur;
            },

            moveH: operation(null, function(dir, unit) {
                var sel = this.doc.sel, pos;
                if (sel.shift || sel.extend || posEq(sel.from, sel.to))
                    pos = findPosH(this.doc, sel.head, dir, unit, this.options.rtlMoveVisually);
                else
                    pos = dir < 0 ? sel.from : sel.to;
                extendSelection(this.doc, pos, pos, dir);
            }),

            deleteH: operation(null, function(dir, unit) {
                var sel = this.doc.sel;
                if (!posEq(sel.from, sel.to)) replaceRange(this.doc, "", sel.from, sel.to, "+delete");
                else replaceRange(this.doc, "", sel.from, findPosH(this.doc, sel.head, dir, unit, false), "+delete");
                this.curOp.userSelChange = true;
            }),

            findPosV: function(from, amount, unit, goalColumn) {
                var dir = 1, x = goalColumn;
                if (amount < 0) { dir = -1; amount = -amount; }
                for (var i = 0, cur = clipPos(this.doc, from); i < amount; ++i) {
                    var coords = cursorCoords(this, cur, "div");
                    if (x == null) x = coords.left;
                    else coords.left = x;
                    cur = findPosV(this, coords, dir, unit);
                    if (cur.hitSide) break;
                }
                return cur;
            },

            moveV: operation(null, function(dir, unit) {
                var sel = this.doc.sel;
                var pos = cursorCoords(this, sel.head, "div");
                if (sel.goalColumn != null) pos.left = sel.goalColumn;
                var target = findPosV(this, pos, dir, unit);

                if (unit == "page") addToScrollPos(this, 0, charCoords(this, target, "div").top - pos.top);
                extendSelection(this.doc, target, target, dir);
                sel.goalColumn = pos.left;
            }),

            toggleOverwrite: function(value) {
                if (value != null && value == this.state.overwrite) return;
                if (this.state.overwrite = !this.state.overwrite)
                    this.display.cursor.className += " CodeMirror-overwrite";
                else
                    this.display.cursor.className = this.display.cursor.className.replace(" CodeMirror-overwrite", "");
            },
            hasFocus: function() { return this.state.focused; },

            scrollTo: operation(null, function(x, y) {
                updateScrollPos(this, x, y);
            }),
            getScrollInfo: function() {
                var scroller = this.display.scroller, co = scrollerCutOff;
                return {left: scroller.scrollLeft, top: scroller.scrollTop,
                    height: scroller.scrollHeight - co, width: scroller.scrollWidth - co,
                    clientHeight: scroller.clientHeight - co, clientWidth: scroller.clientWidth - co};
            },

            scrollIntoView: operation(null, function(pos, margin) {
                if (typeof pos == "number") pos = Pos(pos, 0);
                if (!margin) margin = 0;
                var coords = pos;

                if (!pos || pos.line != null) {
                    this.curOp.scrollToPos = pos ? clipPos(this.doc, pos) : this.doc.sel.head;
                    this.curOp.scrollToPosMargin = margin;
                    coords = cursorCoords(this, this.curOp.scrollToPos);
                }
                var sPos = calculateScrollPos(this, coords.left, coords.top - margin, coords.right, coords.bottom + margin);
                updateScrollPos(this, sPos.scrollLeft, sPos.scrollTop);
            }),

            setSize: operation(null, function(width, height) {
                function interpret(val) {
                    return typeof val == "number" || /^\d+$/.test(String(val)) ? val + "px" : val;
                }
                if (width != null) this.display.wrapper.style.width = interpret(width);
                if (height != null) this.display.wrapper.style.height = interpret(height);
                if (this.options.lineWrapping)
                    this.display.measureLineCache.length = this.display.measureLineCachePos = 0;
                this.curOp.forceUpdate = true;
            }),

            operation: function(f){return runInOp(this, f);},

            refresh: operation(null, function() {
                clearCaches(this);
                updateScrollPos(this, this.doc.scrollLeft, this.doc.scrollTop);
                regChange(this);
            }),

            swapDoc: operation(null, function(doc) {
                var old = this.doc;
                old.cm = null;
                attachDoc(this, doc);
                clearCaches(this);
                resetInput(this, true);
                updateScrollPos(this, doc.scrollLeft, doc.scrollTop);
                return old;
            }),

            getInputField: function(){return this.display.input;},
            getWrapperElement: function(){return this.display.wrapper;},
            getScrollerElement: function(){return this.display.scroller;},
            getGutterElement: function(){return this.display.gutters;}
        };
        eventMixin(CodeMirror);

        // OPTION DEFAULTS

        var optionHandlers = CodeMirror.optionHandlers = {};

        // The default configuration options.
        var defaults = CodeMirror.defaults = {};

        function option(name, deflt, handle, notOnInit) {
            CodeMirror.defaults[name] = deflt;
            if (handle) optionHandlers[name] =
                notOnInit ? function(cm, val, old) {if (old != Init) handle(cm, val, old);} : handle;
        }

        var Init = CodeMirror.Init = {toString: function(){return "CodeMirror.Init";}};

        // These two are, on init, called from the constructor because they
        // have to be initialized before the editor can start at all.
        option("value", "", function(cm, val) {
            cm.setValue(val);
        }, true);
        option("mode", null, function(cm, val) {
            cm.doc.modeOption = val;
            loadMode(cm);
        }, true);

        option("indentUnit", 2, loadMode, true);
        option("indentWithTabs", false);
        option("smartIndent", true);
        option("tabSize", 4, function(cm) {
            loadMode(cm);
            clearCaches(cm);
            regChange(cm);
        }, true);
        option("electricChars", true);
        option("rtlMoveVisually", !windows);

        option("theme", "default", function(cm) {
            themeChanged(cm);
            guttersChanged(cm);
        }, true);
        option("keyMap", "default", keyMapChanged);
        option("extraKeys", null);

        option("onKeyEvent", null);
        option("onDragEvent", null);

        option("lineWrapping", false, wrappingChanged, true);
        option("gutters", [], function(cm) {
            setGuttersForLineNumbers(cm.options);
            guttersChanged(cm);
        }, true);
        option("fixedGutter", true, function(cm, val) {
            cm.display.gutters.style.left = val ? compensateForHScroll(cm.display) + "px" : "0";
            cm.refresh();
        }, true);
        option("coverGutterNextToScrollbar", false, updateScrollbars, true);
        option("lineNumbers", false, function(cm) {
            setGuttersForLineNumbers(cm.options);
            guttersChanged(cm);
        }, true);
        option("firstLineNumber", 1, guttersChanged, true);
        option("lineNumberFormatter", function(integer) {return integer;}, guttersChanged, true);
        option("showCursorWhenSelecting", false, updateSelection, true);

        option("readOnly", false, function(cm, val) {
            if (val == "nocursor") {onBlur(cm); cm.display.input.blur();}
            else if (!val) resetInput(cm, true);
        });
        option("dragDrop", true);

        option("cursorBlinkRate", 530);
        option("cursorScrollMargin", 0);
        option("cursorHeight", 1);
        option("workTime", 100);
        option("workDelay", 100);
        option("flattenSpans", true);
        option("pollInterval", 100);
        option("undoDepth", 40, function(cm, val){cm.doc.history.undoDepth = val;});
        option("historyEventDelay", 500);
        option("viewportMargin", 10, function(cm){cm.refresh();}, true);
        option("maxHighlightLength", 10000, function(cm){loadMode(cm); cm.refresh();}, true);
        option("moveInputWithCursor", true, function(cm, val) {
            if (!val) cm.display.inputDiv.style.top = cm.display.inputDiv.style.left = 0;
        });

        option("tabindex", null, function(cm, val) {
            cm.display.input.tabIndex = val || "";
        });
        option("autofocus", null);

        // MODE DEFINITION AND QUERYING

        // Known modes, by name and by MIME
        var modes = CodeMirror.modes = {}, mimeModes = CodeMirror.mimeModes = {};

        CodeMirror.defineMode = function(name, mode) {
            if (!CodeMirror.defaults.mode && name != "null") CodeMirror.defaults.mode = name;
            if (arguments.length > 2) {
                mode.dependencies = [];
                for (var i = 2; i < arguments.length; ++i) mode.dependencies.push(arguments[i]);
            }
            modes[name] = mode;
        };

        CodeMirror.defineMIME = function(mime, spec) {
            mimeModes[mime] = spec;
        };

        CodeMirror.resolveMode = function(spec) {
            if (typeof spec == "string" && mimeModes.hasOwnProperty(spec)) {
                spec = mimeModes[spec];
            } else if (spec && typeof spec.name == "string" && mimeModes.hasOwnProperty(spec.name)) {
                var found = mimeModes[spec.name];
                spec = createObj(found, spec);
                spec.name = found.name;
            } else if (typeof spec == "string" && /^[\w\-]+\/[\w\-]+\+xml$/.test(spec)) {
                return CodeMirror.resolveMode("application/xml");
            }
            if (typeof spec == "string") return {name: spec};
            else return spec || {name: "null"};
        };

        CodeMirror.getMode = function(options, spec) {
            var spec = CodeMirror.resolveMode(spec);
            var mfactory = modes[spec.name];
            if (!mfactory) return CodeMirror.getMode(options, "text/plain");
            var modeObj = mfactory(options, spec);
            if (modeExtensions.hasOwnProperty(spec.name)) {
                var exts = modeExtensions[spec.name];
                for (var prop in exts) {
                    if (!exts.hasOwnProperty(prop)) continue;
                    if (modeObj.hasOwnProperty(prop)) modeObj["_" + prop] = modeObj[prop];
                    modeObj[prop] = exts[prop];
                }
            }
            modeObj.name = spec.name;

            return modeObj;
        };

        CodeMirror.defineMode("null", function() {
            return {token: function(stream) {stream.skipToEnd();}};
        });
        CodeMirror.defineMIME("text/plain", "null");

        var modeExtensions = CodeMirror.modeExtensions = {};
        CodeMirror.extendMode = function(mode, properties) {
            var exts = modeExtensions.hasOwnProperty(mode) ? modeExtensions[mode] : (modeExtensions[mode] = {});
            copyObj(properties, exts);
        };

        // EXTENSIONS

        CodeMirror.defineExtension = function(name, func) {
            CodeMirror.prototype[name] = func;
        };
        CodeMirror.defineDocExtension = function(name, func) {
            Doc.prototype[name] = func;
        };
        CodeMirror.defineOption = option;

        var initHooks = [];
        CodeMirror.defineInitHook = function(f) {initHooks.push(f);};

        var helpers = CodeMirror.helpers = {};
        CodeMirror.registerHelper = function(type, name, value) {
            if (!helpers.hasOwnProperty(type)) helpers[type] = CodeMirror[type] = {};
            helpers[type][name] = value;
        };

        // UTILITIES

        CodeMirror.isWordChar = isWordChar;

        // MODE STATE HANDLING

        // Utility functions for working with state. Exported because modes
        // sometimes need to do this.
        function copyState(mode, state) {
            if (state === true) return state;
            if (mode.copyState) return mode.copyState(state);
            var nstate = {};
            for (var n in state) {
                var val = state[n];
                if (val instanceof Array) val = val.concat([]);
                nstate[n] = val;
            }
            return nstate;
        }
        CodeMirror.copyState = copyState;

        function startState(mode, a1, a2) {
            return mode.startState ? mode.startState(a1, a2) : true;
        }
        CodeMirror.startState = startState;

        CodeMirror.innerMode = function(mode, state) {
            while (mode.innerMode) {
                var info = mode.innerMode(state);
                if (!info || info.mode == mode) break;
                state = info.state;
                mode = info.mode;
            }
            return info || {mode: mode, state: state};
        };

        // STANDARD COMMANDS

        var commands = CodeMirror.commands = {
            selectAll: function(cm) {cm.setSelection(Pos(cm.firstLine(), 0), Pos(cm.lastLine()));},
            killLine: function(cm) {
                var from = cm.getCursor(true), to = cm.getCursor(false), sel = !posEq(from, to);
                if (!sel && cm.getLine(from.line).length == from.ch)
                    cm.replaceRange("", from, Pos(from.line + 1, 0), "+delete");
                else cm.replaceRange("", from, sel ? to : Pos(from.line), "+delete");
            },
            deleteLine: function(cm) {
                var l = cm.getCursor().line;
                cm.replaceRange("", Pos(l, 0), Pos(l), "+delete");
            },
            delLineLeft: function(cm) {
                var cur = cm.getCursor();
                cm.replaceRange("", Pos(cur.line, 0), cur, "+delete");
            },
            undo: function(cm) {cm.undo();},
            redo: function(cm) {cm.redo();},
            goDocStart: function(cm) {cm.extendSelection(Pos(cm.firstLine(), 0));},
            goDocEnd: function(cm) {cm.extendSelection(Pos(cm.lastLine()));},
            goLineStart: function(cm) {
                cm.extendSelection(lineStart(cm, cm.getCursor().line));
            },
            goLineStartSmart: function(cm) {
                var cur = cm.getCursor(), start = lineStart(cm, cur.line);
                var line = cm.getLineHandle(start.line);
                var order = getOrder(line);
                if (!order || order[0].level == 0) {
                    var firstNonWS = Math.max(0, line.text.search(/\S/));
                    var inWS = cur.line == start.line && cur.ch <= firstNonWS && cur.ch;
                    cm.extendSelection(Pos(start.line, inWS ? 0 : firstNonWS));
                } else cm.extendSelection(start);
            },
            goLineEnd: function(cm) {
                cm.extendSelection(lineEnd(cm, cm.getCursor().line));
            },
            goLineRight: function(cm) {
                var top = cm.charCoords(cm.getCursor(), "div").top + 5;
                cm.extendSelection(cm.coordsChar({left: cm.display.lineDiv.offsetWidth + 100, top: top}, "div"));
            },
            goLineLeft: function(cm) {
                var top = cm.charCoords(cm.getCursor(), "div").top + 5;
                cm.extendSelection(cm.coordsChar({left: 0, top: top}, "div"));
            },
            goLineUp: function(cm) {cm.moveV(-1, "line");},
            goLineDown: function(cm) {cm.moveV(1, "line");},
            goPageUp: function(cm) {cm.moveV(-1, "page");},
            goPageDown: function(cm) {cm.moveV(1, "page");},
            goCharLeft: function(cm) {cm.moveH(-1, "char");},
            goCharRight: function(cm) {cm.moveH(1, "char");},
            goColumnLeft: function(cm) {cm.moveH(-1, "column");},
            goColumnRight: function(cm) {cm.moveH(1, "column");},
            goWordLeft: function(cm) {cm.moveH(-1, "word");},
            goGroupRight: function(cm) {cm.moveH(1, "group");},
            goGroupLeft: function(cm) {cm.moveH(-1, "group");},
            goWordRight: function(cm) {cm.moveH(1, "word");},
            delCharBefore: function(cm) {cm.deleteH(-1, "char");},
            delCharAfter: function(cm) {cm.deleteH(1, "char");},
            delWordBefore: function(cm) {cm.deleteH(-1, "word");},
            delWordAfter: function(cm) {cm.deleteH(1, "word");},
            delGroupBefore: function(cm) {cm.deleteH(-1, "group");},
            delGroupAfter: function(cm) {cm.deleteH(1, "group");},
            indentAuto: function(cm) {cm.indentSelection("smart");},
            indentMore: function(cm) {cm.indentSelection("add");},
            indentLess: function(cm) {cm.indentSelection("subtract");},
            insertTab: function(cm) {cm.replaceSelection("\t", "end", "+input");},
            defaultTab: function(cm) {
                if (cm.somethingSelected()) cm.indentSelection("add");
                else cm.replaceSelection("\t", "end", "+input");
            },
            transposeChars: function(cm) {
                var cur = cm.getCursor(), line = cm.getLine(cur.line);
                if (cur.ch > 0 && cur.ch < line.length - 1)
                    cm.replaceRange(line.charAt(cur.ch) + line.charAt(cur.ch - 1),
                        Pos(cur.line, cur.ch - 1), Pos(cur.line, cur.ch + 1));
            },
            newlineAndIndent: function(cm) {
                operation(cm, function() {
                    cm.replaceSelection("\n", "end", "+input");
                    cm.indentLine(cm.getCursor().line, null, true);
                })();
            },
            toggleOverwrite: function(cm) {cm.toggleOverwrite();}
        };

        // STANDARD KEYMAPS

        var keyMap = CodeMirror.keyMap = {};
        keyMap.basic = {
            "Left": "goCharLeft", "Right": "goCharRight", "Up": "goLineUp", "Down": "goLineDown",
            "End": "goLineEnd", "Home": "goLineStartSmart", "PageUp": "goPageUp", "PageDown": "goPageDown",
            "Delete": "delCharAfter", "Backspace": "delCharBefore", "Tab": "defaultTab", "Shift-Tab": "indentAuto",
            "Enter": "newlineAndIndent", "Insert": "toggleOverwrite"
        };
        // Note that the save and find-related commands aren't defined by
        // default. Unknown commands are simply ignored.
        keyMap.pcDefault = {
            "Ctrl-A": "selectAll", "Ctrl-D": "deleteLine", "Ctrl-Z": "undo", "Shift-Ctrl-Z": "redo", "Ctrl-Y": "redo",
            "Ctrl-Home": "goDocStart", "Alt-Up": "goDocStart", "Ctrl-End": "goDocEnd", "Ctrl-Down": "goDocEnd",
            "Ctrl-Left": "goGroupLeft", "Ctrl-Right": "goGroupRight", "Alt-Left": "goLineStart", "Alt-Right": "goLineEnd",
            "Ctrl-Backspace": "delGroupBefore", "Ctrl-Delete": "delGroupAfter", "Ctrl-S": "save", "Ctrl-F": "find",
            "Ctrl-G": "findNext", "Shift-Ctrl-G": "findPrev", "Shift-Ctrl-F": "replace", "Shift-Ctrl-R": "replaceAll",
            "Ctrl-[": "indentLess", "Ctrl-]": "indentMore",
            fallthrough: "basic"
        };
        keyMap.macDefault = {
            "Cmd-A": "selectAll", "Cmd-D": "deleteLine", "Cmd-Z": "undo", "Shift-Cmd-Z": "redo", "Cmd-Y": "redo",
            "Cmd-Up": "goDocStart", "Cmd-End": "goDocEnd", "Cmd-Down": "goDocEnd", "Alt-Left": "goGroupLeft",
            "Alt-Right": "goGroupRight", "Cmd-Left": "goLineStart", "Cmd-Right": "goLineEnd", "Alt-Backspace": "delGroupBefore",
            "Ctrl-Alt-Backspace": "delGroupAfter", "Alt-Delete": "delGroupAfter", "Cmd-S": "save", "Cmd-F": "find",
            "Cmd-G": "findNext", "Shift-Cmd-G": "findPrev", "Cmd-Alt-F": "replace", "Shift-Cmd-Alt-F": "replaceAll",
            "Cmd-[": "indentLess", "Cmd-]": "indentMore", "Cmd-Backspace": "delLineLeft",
            fallthrough: ["basic", "emacsy"]
        };
        keyMap["default"] = mac ? keyMap.macDefault : keyMap.pcDefault;
        keyMap.emacsy = {
            "Ctrl-F": "goCharRight", "Ctrl-B": "goCharLeft", "Ctrl-P": "goLineUp", "Ctrl-N": "goLineDown",
            "Alt-F": "goWordRight", "Alt-B": "goWordLeft", "Ctrl-A": "goLineStart", "Ctrl-E": "goLineEnd",
            "Ctrl-V": "goPageDown", "Shift-Ctrl-V": "goPageUp", "Ctrl-D": "delCharAfter", "Ctrl-H": "delCharBefore",
            "Alt-D": "delWordAfter", "Alt-Backspace": "delWordBefore", "Ctrl-K": "killLine", "Ctrl-T": "transposeChars"
        };

        // KEYMAP DISPATCH

        function getKeyMap(val) {
            if (typeof val == "string") return keyMap[val];
            else return val;
        }

        function lookupKey(name, maps, handle) {
            function lookup(map) {
                map = getKeyMap(map);
                var found = map[name];
                if (found === false) return "stop";
                if (found != null && handle(found)) return true;
                if (map.nofallthrough) return "stop";

                var fallthrough = map.fallthrough;
                if (fallthrough == null) return false;
                if (Object.prototype.toString.call(fallthrough) != "[object Array]")
                    return lookup(fallthrough);
                for (var i = 0, e = fallthrough.length; i < e; ++i) {
                    var done = lookup(fallthrough[i]);
                    if (done) return done;
                }
                return false;
            }

            for (var i = 0; i < maps.length; ++i) {
                var done = lookup(maps[i]);
                if (done) return done != "stop";
            }
        }
        function isModifierKey(event) {
            var name = keyNames[event.keyCode];
            return name == "Ctrl" || name == "Alt" || name == "Shift" || name == "Mod";
        }
        function keyName(event, noShift) {
            if (opera && event.keyCode == 34 && event["char"]) return false;
            var name = keyNames[event.keyCode];
            if (name == null || event.altGraphKey) return false;
            if (event.altKey) name = "Alt-" + name;
            if (flipCtrlCmd ? event.metaKey : event.ctrlKey) name = "Ctrl-" + name;
            if (flipCtrlCmd ? event.ctrlKey : event.metaKey) name = "Cmd-" + name;
            if (!noShift && event.shiftKey) name = "Shift-" + name;
            return name;
        }
        CodeMirror.lookupKey = lookupKey;
        CodeMirror.isModifierKey = isModifierKey;
        CodeMirror.keyName = keyName;

        // FROMTEXTAREA

        CodeMirror.fromTextArea = function(textarea, options) {
            if (!options) options = {};
            options.value = textarea.value;
            if (!options.tabindex && textarea.tabindex)
                options.tabindex = textarea.tabindex;
            if (!options.placeholder && textarea.placeholder)
                options.placeholder = textarea.placeholder;
            // Set autofocus to true if this textarea is focused, or if it has
            // autofocus and no other element is focused.
            if (options.autofocus == null) {
                var hasFocus = document.body;
                // doc.activeElement occasionally throws on IE
                try { hasFocus = document.activeElement; } catch(e) {}
                options.autofocus = hasFocus == textarea ||
                    textarea.getAttribute("autofocus") != null && hasFocus == document.body;
            }

            function save() {textarea.value = cm.getValue();}
            if (textarea.form) {
                on(textarea.form, "submit", save);
                // Deplorable hack to make the submit method do the right thing.
                if (!options.leaveSubmitMethodAlone) {
                    var form = textarea.form, realSubmit = form.submit;
                    try {
                        var wrappedSubmit = form.submit = function() {
                            save();
                            form.submit = realSubmit;
                            form.submit();
                            form.submit = wrappedSubmit;
                        };
                    } catch(e) {}
                }
            }

            textarea.style.display = "none";
            var cm = CodeMirror(function(node) {
                textarea.parentNode.insertBefore(node, textarea.nextSibling);
            }, options);
            cm.save = save;
            cm.getTextArea = function() { return textarea; };
            cm.toTextArea = function() {
                save();
                textarea.parentNode.removeChild(cm.getWrapperElement());
                textarea.style.display = "";
                if (textarea.form) {
                    off(textarea.form, "submit", save);
                    if (typeof textarea.form.submit == "function")
                        textarea.form.submit = realSubmit;
                }
            };
            return cm;
        };

        // STRING STREAM

        // Fed to the mode parsers, provides helper functions to make
        // parsers more succinct.

        // The character stream used by a mode's parser.
        function StringStream(string, tabSize) {
            this.pos = this.start = 0;
            this.string = string;
            this.tabSize = tabSize || 8;
            this.lastColumnPos = this.lastColumnValue = 0;
        }

        StringStream.prototype = {
            eol: function() {return this.pos >= this.string.length;},
            sol: function() {return this.pos == 0;},
            peek: function() {return this.string.charAt(this.pos) || undefined;},
            next: function() {
                if (this.pos < this.string.length)
                    return this.string.charAt(this.pos++);
            },
            eat: function(match) {
                var ch = this.string.charAt(this.pos);
                if (typeof match == "string") var ok = ch == match;
                else var ok = ch && (match.test ? match.test(ch) : match(ch));
                if (ok) {++this.pos; return ch;}
            },
            eatWhile: function(match) {
                var start = this.pos;
                while (this.eat(match)){}
                return this.pos > start;
            },
            eatSpace: function() {
                var start = this.pos;
                while (/[\s\u00a0]/.test(this.string.charAt(this.pos))) ++this.pos;
                return this.pos > start;
            },
            skipToEnd: function() {this.pos = this.string.length;},
            skipTo: function(ch) {
                var found = this.string.indexOf(ch, this.pos);
                if (found > -1) {this.pos = found; return true;}
            },
            backUp: function(n) {this.pos -= n;},
            column: function() {
                if (this.lastColumnPos < this.start) {
                    this.lastColumnValue = countColumn(this.string, this.start, this.tabSize, this.lastColumnPos, this.lastColumnValue);
                    this.lastColumnPos = this.start;
                }
                return this.lastColumnValue;
            },
            indentation: function() {return countColumn(this.string, null, this.tabSize);},
            match: function(pattern, consume, caseInsensitive) {
                if (typeof pattern == "string") {
                    var cased = function(str) {return caseInsensitive ? str.toLowerCase() : str;};
                    var substr = this.string.substr(this.pos, pattern.length);
                    if (cased(substr) == cased(pattern)) {
                        if (consume !== false) this.pos += pattern.length;
                        return true;
                    }
                } else {
                    var match = this.string.slice(this.pos).match(pattern);
                    if (match && match.index > 0) return null;
                    if (match && consume !== false) this.pos += match[0].length;
                    return match;
                }
            },
            current: function(){return this.string.slice(this.start, this.pos);}
        };
        CodeMirror.StringStream = StringStream;

        // TEXTMARKERS

        function TextMarker(doc, type) {
            this.lines = [];
            this.type = type;
            this.doc = doc;
        }
        CodeMirror.TextMarker = TextMarker;
        eventMixin(TextMarker);

        TextMarker.prototype.clear = function() {
            if (this.explicitlyCleared) return;
            var cm = this.doc.cm, withOp = cm && !cm.curOp;
            if (withOp) startOperation(cm);
            if (hasHandler(this, "clear")) {
                var found = this.find();
                if (found) signalLater(this, "clear", found.from, found.to);
            }
            var min = null, max = null;
            for (var i = 0; i < this.lines.length; ++i) {
                var line = this.lines[i];
                var span = getMarkedSpanFor(line.markedSpans, this);
                if (span.to != null) max = lineNo(line);
                line.markedSpans = removeMarkedSpan(line.markedSpans, span);
                if (span.from != null)
                    min = lineNo(line);
                else if (this.collapsed && !lineIsHidden(this.doc, line) && cm)
                    updateLineHeight(line, textHeight(cm.display));
            }
            if (cm && this.collapsed && !cm.options.lineWrapping) for (var i = 0; i < this.lines.length; ++i) {
                var visual = visualLine(cm.doc, this.lines[i]), len = lineLength(cm.doc, visual);
                if (len > cm.display.maxLineLength) {
                    cm.display.maxLine = visual;
                    cm.display.maxLineLength = len;
                    cm.display.maxLineChanged = true;
                }
            }

            if (min != null && cm) regChange(cm, min, max + 1);
            this.lines.length = 0;
            this.explicitlyCleared = true;
            if (this.atomic && this.doc.cantEdit) {
                this.doc.cantEdit = false;
                if (cm) reCheckSelection(cm);
            }
            if (withOp) endOperation(cm);
        };

        TextMarker.prototype.find = function() {
            var from, to;
            for (var i = 0; i < this.lines.length; ++i) {
                var line = this.lines[i];
                var span = getMarkedSpanFor(line.markedSpans, this);
                if (span.from != null || span.to != null) {
                    var found = lineNo(line);
                    if (span.from != null) from = Pos(found, span.from);
                    if (span.to != null) to = Pos(found, span.to);
                }
            }
            if (this.type == "bookmark") return from;
            return from && {from: from, to: to};
        };

        TextMarker.prototype.changed = function() {
            var pos = this.find(), cm = this.doc.cm;
            if (!pos || !cm) return;
            var line = getLine(this.doc, pos.from.line);
            clearCachedMeasurement(cm, line);
            if (pos.from.line >= cm.display.showingFrom && pos.from.line < cm.display.showingTo) {
                for (var node = cm.display.lineDiv.firstChild; node; node = node.nextSibling) if (node.lineObj == line) {
                    if (node.offsetHeight != line.height) updateLineHeight(line, node.offsetHeight);
                    break;
                }
                runInOp(cm, function() {
                    cm.curOp.selectionChanged = cm.curOp.forceUpdate = cm.curOp.updateMaxLine = true;
                });
            }
        };

        TextMarker.prototype.attachLine = function(line) {
            if (!this.lines.length && this.doc.cm) {
                var op = this.doc.cm.curOp;
                if (!op.maybeHiddenMarkers || indexOf(op.maybeHiddenMarkers, this) == -1)
                    (op.maybeUnhiddenMarkers || (op.maybeUnhiddenMarkers = [])).push(this);
            }
            this.lines.push(line);
        };
        TextMarker.prototype.detachLine = function(line) {
            this.lines.splice(indexOf(this.lines, line), 1);
            if (!this.lines.length && this.doc.cm) {
                var op = this.doc.cm.curOp;
                (op.maybeHiddenMarkers || (op.maybeHiddenMarkers = [])).push(this);
            }
        };

        function markText(doc, from, to, options, type) {
            if (options && options.shared) return markTextShared(doc, from, to, options, type);
            if (doc.cm && !doc.cm.curOp) return operation(doc.cm, markText)(doc, from, to, options, type);

            var marker = new TextMarker(doc, type);
            if (type == "range" && !posLess(from, to)) return marker;
            if (options) copyObj(options, marker);
            if (marker.replacedWith) {
                marker.collapsed = true;
                marker.replacedWith = elt("span", [marker.replacedWith], "CodeMirror-widget");
                if (!options.handleMouseEvents) marker.replacedWith.ignoreEvents = true;
            }
            if (marker.collapsed) sawCollapsedSpans = true;

            if (marker.addToHistory)
                addToHistory(doc, {from: from, to: to, origin: "markText"},
                    {head: doc.sel.head, anchor: doc.sel.anchor}, NaN);

            var curLine = from.line, size = 0, collapsedAtStart, collapsedAtEnd, cm = doc.cm, updateMaxLine;
            doc.iter(curLine, to.line + 1, function(line) {
                if (cm && marker.collapsed && !cm.options.lineWrapping && visualLine(doc, line) == cm.display.maxLine)
                    updateMaxLine = true;
                var span = {from: null, to: null, marker: marker};
                size += line.text.length;
                if (curLine == from.line) {span.from = from.ch; size -= from.ch;}
                if (curLine == to.line) {span.to = to.ch; size -= line.text.length - to.ch;}
                if (marker.collapsed) {
                    if (curLine == to.line) collapsedAtEnd = collapsedSpanAt(line, to.ch);
                    if (curLine == from.line) collapsedAtStart = collapsedSpanAt(line, from.ch);
                    else updateLineHeight(line, 0);
                }
                addMarkedSpan(line, span);
                ++curLine;
            });
            if (marker.collapsed) doc.iter(from.line, to.line + 1, function(line) {
                if (lineIsHidden(doc, line)) updateLineHeight(line, 0);
            });

            if (marker.clearOnEnter) on(marker, "beforeCursorEnter", function() { marker.clear(); });

            if (marker.readOnly) {
                sawReadOnlySpans = true;
                if (doc.history.done.length || doc.history.undone.length)
                    doc.clearHistory();
            }
            if (marker.collapsed) {
                if (collapsedAtStart != collapsedAtEnd)
                    throw new Error("Inserting collapsed marker overlapping an existing one");
                marker.size = size;
                marker.atomic = true;
            }
            if (cm) {
                if (updateMaxLine) cm.curOp.updateMaxLine = true;
                if (marker.className || marker.title || marker.startStyle || marker.endStyle || marker.collapsed)
                    regChange(cm, from.line, to.line + 1);
                if (marker.atomic) reCheckSelection(cm);
            }
            return marker;
        }

        // SHARED TEXTMARKERS

        function SharedTextMarker(markers, primary) {
            this.markers = markers;
            this.primary = primary;
            for (var i = 0, me = this; i < markers.length; ++i) {
                markers[i].parent = this;
                on(markers[i], "clear", function(){me.clear();});
            }
        }
        CodeMirror.SharedTextMarker = SharedTextMarker;
        eventMixin(SharedTextMarker);

        SharedTextMarker.prototype.clear = function() {
            if (this.explicitlyCleared) return;
            this.explicitlyCleared = true;
            for (var i = 0; i < this.markers.length; ++i)
                this.markers[i].clear();
            signalLater(this, "clear");
        };
        SharedTextMarker.prototype.find = function() {
            return this.primary.find();
        };

        function markTextShared(doc, from, to, options, type) {
            options = copyObj(options);
            options.shared = false;
            var markers = [markText(doc, from, to, options, type)], primary = markers[0];
            var widget = options.replacedWith;
            linkedDocs(doc, function(doc) {
                if (widget) options.replacedWith = widget.cloneNode(true);
                markers.push(markText(doc, clipPos(doc, from), clipPos(doc, to), options, type));
                for (var i = 0; i < doc.linked.length; ++i)
                    if (doc.linked[i].isParent) return;
                primary = lst(markers);
            });
            return new SharedTextMarker(markers, primary);
        }

        // TEXTMARKER SPANS

        function getMarkedSpanFor(spans, marker) {
            if (spans) for (var i = 0; i < spans.length; ++i) {
                var span = spans[i];
                if (span.marker == marker) return span;
            }
        }
        function removeMarkedSpan(spans, span) {
            for (var r, i = 0; i < spans.length; ++i)
                if (spans[i] != span) (r || (r = [])).push(spans[i]);
            return r;
        }
        function addMarkedSpan(line, span) {
            line.markedSpans = line.markedSpans ? line.markedSpans.concat([span]) : [span];
            span.marker.attachLine(line);
        }

        function markedSpansBefore(old, startCh, isInsert) {
            if (old) for (var i = 0, nw; i < old.length; ++i) {
                var span = old[i], marker = span.marker;
                var startsBefore = span.from == null || (marker.inclusiveLeft ? span.from <= startCh : span.from < startCh);
                if (startsBefore || marker.type == "bookmark" && span.from == startCh && (!isInsert || !span.marker.insertLeft)) {
                    var endsAfter = span.to == null || (marker.inclusiveRight ? span.to >= startCh : span.to > startCh);
                    (nw || (nw = [])).push({from: span.from,
                        to: endsAfter ? null : span.to,
                        marker: marker});
                }
            }
            return nw;
        }

        function markedSpansAfter(old, endCh, isInsert) {
            if (old) for (var i = 0, nw; i < old.length; ++i) {
                var span = old[i], marker = span.marker;
                var endsAfter = span.to == null || (marker.inclusiveRight ? span.to >= endCh : span.to > endCh);
                if (endsAfter || marker.type == "bookmark" && span.from == endCh && (!isInsert || span.marker.insertLeft)) {
                    var startsBefore = span.from == null || (marker.inclusiveLeft ? span.from <= endCh : span.from < endCh);
                    (nw || (nw = [])).push({from: startsBefore ? null : span.from - endCh,
                        to: span.to == null ? null : span.to - endCh,
                        marker: marker});
                }
            }
            return nw;
        }

        function stretchSpansOverChange(doc, change) {
            var oldFirst = isLine(doc, change.from.line) && getLine(doc, change.from.line).markedSpans;
            var oldLast = isLine(doc, change.to.line) && getLine(doc, change.to.line).markedSpans;
            if (!oldFirst && !oldLast) return null;

            var startCh = change.from.ch, endCh = change.to.ch, isInsert = posEq(change.from, change.to);
            // Get the spans that 'stick out' on both sides
            var first = markedSpansBefore(oldFirst, startCh, isInsert);
            var last = markedSpansAfter(oldLast, endCh, isInsert);

            // Next, merge those two ends
            var sameLine = change.text.length == 1, offset = lst(change.text).length + (sameLine ? startCh : 0);
            if (first) {
                // Fix up .to properties of first
                for (var i = 0; i < first.length; ++i) {
                    var span = first[i];
                    if (span.to == null) {
                        var found = getMarkedSpanFor(last, span.marker);
                        if (!found) span.to = startCh;
                        else if (sameLine) span.to = found.to == null ? null : found.to + offset;
                    }
                }
            }
            if (last) {
                // Fix up .from in last (or move them into first in case of sameLine)
                for (var i = 0; i < last.length; ++i) {
                    var span = last[i];
                    if (span.to != null) span.to += offset;
                    if (span.from == null) {
                        var found = getMarkedSpanFor(first, span.marker);
                        if (!found) {
                            span.from = offset;
                            if (sameLine) (first || (first = [])).push(span);
                        }
                    } else {
                        span.from += offset;
                        if (sameLine) (first || (first = [])).push(span);
                    }
                }
            }
            if (sameLine && first) {
                // Make sure we didn't create any zero-length spans
                for (var i = 0; i < first.length; ++i)
                    if (first[i].from != null && first[i].from == first[i].to && first[i].marker.type != "bookmark")
                        first.splice(i--, 1);
                if (!first.length) first = null;
            }

            var newMarkers = [first];
            if (!sameLine) {
                // Fill gap with whole-line-spans
                var gap = change.text.length - 2, gapMarkers;
                if (gap > 0 && first)
                    for (var i = 0; i < first.length; ++i)
                        if (first[i].to == null)
                            (gapMarkers || (gapMarkers = [])).push({from: null, to: null, marker: first[i].marker});
                for (var i = 0; i < gap; ++i)
                    newMarkers.push(gapMarkers);
                newMarkers.push(last);
            }
            return newMarkers;
        }

        function mergeOldSpans(doc, change) {
            var old = getOldSpans(doc, change);
            var stretched = stretchSpansOverChange(doc, change);
            if (!old) return stretched;
            if (!stretched) return old;

            for (var i = 0; i < old.length; ++i) {
                var oldCur = old[i], stretchCur = stretched[i];
                if (oldCur && stretchCur) {
                    spans: for (var j = 0; j < stretchCur.length; ++j) {
                        var span = stretchCur[j];
                        for (var k = 0; k < oldCur.length; ++k)
                            if (oldCur[k].marker == span.marker) continue spans;
                        oldCur.push(span);
                    }
                } else if (stretchCur) {
                    old[i] = stretchCur;
                }
            }
            return old;
        }

        function removeReadOnlyRanges(doc, from, to) {
            var markers = null;
            doc.iter(from.line, to.line + 1, function(line) {
                if (line.markedSpans) for (var i = 0; i < line.markedSpans.length; ++i) {
                    var mark = line.markedSpans[i].marker;
                    if (mark.readOnly && (!markers || indexOf(markers, mark) == -1))
                        (markers || (markers = [])).push(mark);
                }
            });
            if (!markers) return null;
            var parts = [{from: from, to: to}];
            for (var i = 0; i < markers.length; ++i) {
                var mk = markers[i], m = mk.find();
                for (var j = 0; j < parts.length; ++j) {
                    var p = parts[j];
                    if (posLess(p.to, m.from) || posLess(m.to, p.from)) continue;
                    var newParts = [j, 1];
                    if (posLess(p.from, m.from) || !mk.inclusiveLeft && posEq(p.from, m.from))
                        newParts.push({from: p.from, to: m.from});
                    if (posLess(m.to, p.to) || !mk.inclusiveRight && posEq(p.to, m.to))
                        newParts.push({from: m.to, to: p.to});
                    parts.splice.apply(parts, newParts);
                    j += newParts.length - 1;
                }
            }
            return parts;
        }

        function collapsedSpanAt(line, ch) {
            var sps = sawCollapsedSpans && line.markedSpans, found;
            if (sps) for (var sp, i = 0; i < sps.length; ++i) {
                sp = sps[i];
                if (!sp.marker.collapsed) continue;
                if ((sp.from == null || sp.from < ch) &&
                    (sp.to == null || sp.to > ch) &&
                    (!found || found.width < sp.marker.width))
                    found = sp.marker;
            }
            return found;
        }
        function collapsedSpanAtStart(line) { return collapsedSpanAt(line, -1); }
        function collapsedSpanAtEnd(line) { return collapsedSpanAt(line, line.text.length + 1); }

        function visualLine(doc, line) {
            var merged;
            while (merged = collapsedSpanAtStart(line))
                line = getLine(doc, merged.find().from.line);
            return line;
        }

        function lineIsHidden(doc, line) {
            var sps = sawCollapsedSpans && line.markedSpans;
            if (sps) for (var sp, i = 0; i < sps.length; ++i) {
                sp = sps[i];
                if (!sp.marker.collapsed) continue;
                if (sp.from == null) return true;
                if (sp.marker.replacedWith) continue;
                if (sp.from == 0 && sp.marker.inclusiveLeft && lineIsHiddenInner(doc, line, sp))
                    return true;
            }
        }
        function lineIsHiddenInner(doc, line, span) {
            if (span.to == null) {
                var end = span.marker.find().to, endLine = getLine(doc, end.line);
                return lineIsHiddenInner(doc, endLine, getMarkedSpanFor(endLine.markedSpans, span.marker));
            }
            if (span.marker.inclusiveRight && span.to == line.text.length)
                return true;
            for (var sp, i = 0; i < line.markedSpans.length; ++i) {
                sp = line.markedSpans[i];
                if (sp.marker.collapsed && !sp.marker.replacedWith && sp.from == span.to &&
                    (sp.marker.inclusiveLeft || span.marker.inclusiveRight) &&
                    lineIsHiddenInner(doc, line, sp)) return true;
            }
        }

        function detachMarkedSpans(line) {
            var spans = line.markedSpans;
            if (!spans) return;
            for (var i = 0; i < spans.length; ++i)
                spans[i].marker.detachLine(line);
            line.markedSpans = null;
        }

        function attachMarkedSpans(line, spans) {
            if (!spans) return;
            for (var i = 0; i < spans.length; ++i)
                spans[i].marker.attachLine(line);
            line.markedSpans = spans;
        }

        // LINE WIDGETS

        var LineWidget = CodeMirror.LineWidget = function(cm, node, options) {
            if (options) for (var opt in options) if (options.hasOwnProperty(opt))
                this[opt] = options[opt];
            this.cm = cm;
            this.node = node;
        };
        eventMixin(LineWidget);
        function widgetOperation(f) {
            return function() {
                var withOp = !this.cm.curOp;
                if (withOp) startOperation(this.cm);
                try {var result = f.apply(this, arguments);}
                finally {if (withOp) endOperation(this.cm);}
                return result;
            };
        }
        LineWidget.prototype.clear = widgetOperation(function() {
            var ws = this.line.widgets, no = lineNo(this.line);
            if (no == null || !ws) return;
            for (var i = 0; i < ws.length; ++i) if (ws[i] == this) ws.splice(i--, 1);
            if (!ws.length) this.line.widgets = null;
            var aboveVisible = heightAtLine(this.cm, this.line) < this.cm.doc.scrollTop;
            updateLineHeight(this.line, Math.max(0, this.line.height - widgetHeight(this)));
            if (aboveVisible) addToScrollPos(this.cm, 0, -this.height);
            regChange(this.cm, no, no + 1);
        });
        LineWidget.prototype.changed = widgetOperation(function() {
            var oldH = this.height;
            this.height = null;
            var diff = widgetHeight(this) - oldH;
            if (!diff) return;
            updateLineHeight(this.line, this.line.height + diff);
            var no = lineNo(this.line);
            regChange(this.cm, no, no + 1);
        });

        function widgetHeight(widget) {
            if (widget.height != null) return widget.height;
            if (!widget.node.parentNode || widget.node.parentNode.nodeType != 1)
                removeChildrenAndAdd(widget.cm.display.measure, elt("div", [widget.node], null, "position: relative"));
            return widget.height = widget.node.offsetHeight;
        }

        function addLineWidget(cm, handle, node, options) {
            var widget = new LineWidget(cm, node, options);
            if (widget.noHScroll) cm.display.alignWidgets = true;
            changeLine(cm, handle, function(line) {
                var widgets = line.widgets || (line.widgets = []);
                if (widget.insertAt == null) widgets.push(widget);
                else widgets.splice(Math.min(widgets.length - 1, Math.max(0, widget.insertAt)), 0, widget);
                widget.line = line;
                if (!lineIsHidden(cm.doc, line) || widget.showIfHidden) {
                    var aboveVisible = heightAtLine(cm, line) < cm.doc.scrollTop;
                    updateLineHeight(line, line.height + widgetHeight(widget));
                    if (aboveVisible) addToScrollPos(cm, 0, widget.height);
                }
                return true;
            });
            return widget;
        }

        // LINE DATA STRUCTURE

        // Line objects. These hold state related to a line, including
        // highlighting info (the styles array).
        var Line = CodeMirror.Line = function(text, markedSpans, estimateHeight) {
            this.text = text;
            attachMarkedSpans(this, markedSpans);
            this.height = estimateHeight ? estimateHeight(this) : 1;
        };
        eventMixin(Line);

        function updateLine(line, text, markedSpans, estimateHeight) {
            line.text = text;
            if (line.stateAfter) line.stateAfter = null;
            if (line.styles) line.styles = null;
            if (line.order != null) line.order = null;
            detachMarkedSpans(line);
            attachMarkedSpans(line, markedSpans);
            var estHeight = estimateHeight ? estimateHeight(line) : 1;
            if (estHeight != line.height) updateLineHeight(line, estHeight);
        }

        function cleanUpLine(line) {
            line.parent = null;
            detachMarkedSpans(line);
        }

        // Run the given mode's parser over a line, update the styles
        // array, which contains alternating fragments of text and CSS
        // classes.
        function runMode(cm, text, mode, state, f) {
            var flattenSpans = mode.flattenSpans;
            if (flattenSpans == null) flattenSpans = cm.options.flattenSpans;
            var curStart = 0, curStyle = null;
            var stream = new StringStream(text, cm.options.tabSize), style;
            if (text == "" && mode.blankLine) mode.blankLine(state);
            while (!stream.eol()) {
                if (stream.pos > cm.options.maxHighlightLength) {
                    flattenSpans = false;
                    // Webkit seems to refuse to render text nodes longer than 57444 characters
                    stream.pos = Math.min(text.length, stream.start + 50000);
                    style = null;
                } else {
                    style = mode.token(stream, state);
                }
                if (!flattenSpans || curStyle != style) {
                    if (curStart < stream.start) f(stream.start, curStyle);
                    curStart = stream.start; curStyle = style;
                }
                stream.start = stream.pos;
            }
            if (curStart < stream.pos) f(stream.pos, curStyle);
        }

        function highlightLine(cm, line, state) {
            // A styles array always starts with a number identifying the
            // mode/overlays that it is based on (for easy invalidation).
            var st = [cm.state.modeGen];
            // Compute the base array of styles
            runMode(cm, line.text, cm.doc.mode, state, function(end, style) {st.push(end, style);});

            // Run overlays, adjust style array.
            for (var o = 0; o < cm.state.overlays.length; ++o) {
                var overlay = cm.state.overlays[o], i = 1, at = 0;
                runMode(cm, line.text, overlay.mode, true, function(end, style) {
                    var start = i;
                    // Ensure there's a token end at the current position, and that i points at it
                    while (at < end) {
                        var i_end = st[i];
                        if (i_end > end)
                            st.splice(i, 1, end, st[i+1], i_end);
                        i += 2;
                        at = Math.min(end, i_end);
                    }
                    if (!style) return;
                    if (overlay.opaque) {
                        st.splice(start, i - start, end, style);
                        i = start + 2;
                    } else {
                        for (; start < i; start += 2) {
                            var cur = st[start+1];
                            st[start+1] = cur ? cur + " " + style : style;
                        }
                    }
                });
            }

            return st;
        }

        function getLineStyles(cm, line) {
            if (!line.styles || line.styles[0] != cm.state.modeGen)
                line.styles = highlightLine(cm, line, line.stateAfter = getStateBefore(cm, lineNo(line)));
            return line.styles;
        }

        // Lightweight form of highlight -- proceed over this line and
        // update state, but don't save a style array.
        function processLine(cm, line, state) {
            var mode = cm.doc.mode;
            var stream = new StringStream(line.text, cm.options.tabSize);
            if (line.text == "" && mode.blankLine) mode.blankLine(state);
            while (!stream.eol() && stream.pos <= cm.options.maxHighlightLength) {
                mode.token(stream, state);
                stream.start = stream.pos;
            }
        }

        var styleToClassCache = {};
        function styleToClass(style) {
            if (!style) return null;
            return styleToClassCache[style] ||
                (styleToClassCache[style] = "cm-" + style.replace(/ +/g, " cm-"));
        }

        function lineContent(cm, realLine, measure, copyWidgets) {
            var merged, line = realLine, empty = true;
            while (merged = collapsedSpanAtStart(line))
                line = getLine(cm.doc, merged.find().from.line);

            var builder = {pre: elt("pre"), col: 0, pos: 0,
                measure: null, measuredSomething: false, cm: cm,
                copyWidgets: copyWidgets};
            if (line.textClass) builder.pre.className = line.textClass;

            do {
                if (line.text) empty = false;
                builder.measure = line == realLine && measure;
                builder.pos = 0;
                builder.addToken = builder.measure ? buildTokenMeasure : buildToken;
                if ((ie || webkit) && cm.getOption("lineWrapping"))
                    builder.addToken = buildTokenSplitSpaces(builder.addToken);
                var next = insertLineContent(line, builder, getLineStyles(cm, line));
                if (measure && line == realLine && !builder.measuredSomething) {
                    measure[0] = builder.pre.appendChild(zeroWidthElement(cm.display.measure));
                    builder.measuredSomething = true;
                }
                if (next) line = getLine(cm.doc, next.to.line);
            } while (next);

            if (measure && !builder.measuredSomething && !measure[0])
                measure[0] = builder.pre.appendChild(empty ? elt("span", "\u00a0") : zeroWidthElement(cm.display.measure));
            if (!builder.pre.firstChild && !lineIsHidden(cm.doc, realLine))
                builder.pre.appendChild(document.createTextNode("\u00a0"));

            var order;
            // Work around problem with the reported dimensions of single-char
            // direction spans on IE (issue #1129). See also the comment in
            // cursorCoords.
            if (measure && ie && (order = getOrder(line))) {
                var l = order.length - 1;
                if (order[l].from == order[l].to) --l;
                var last = order[l], prev = order[l - 1];
                if (last.from + 1 == last.to && prev && last.level < prev.level) {
                    var span = measure[builder.pos - 1];
                    if (span) span.parentNode.insertBefore(span.measureRight = zeroWidthElement(cm.display.measure),
                        span.nextSibling);
                }
            }

            signal(cm, "renderLine", cm, realLine, builder.pre);
            return builder.pre;
        }

        var tokenSpecialChars = /[\t\u0000-\u0019\u00ad\u200b\u2028\u2029\uFEFF]/g;
        function buildToken(builder, text, style, startStyle, endStyle, title) {
            if (!text) return;
            if (!tokenSpecialChars.test(text)) {
                builder.col += text.length;
                var content = document.createTextNode(text);
            } else {
                var content = document.createDocumentFragment(), pos = 0;
                while (true) {
                    tokenSpecialChars.lastIndex = pos;
                    var m = tokenSpecialChars.exec(text);
                    var skipped = m ? m.index - pos : text.length - pos;
                    if (skipped) {
                        content.appendChild(document.createTextNode(text.slice(pos, pos + skipped)));
                        builder.col += skipped;
                    }
                    if (!m) break;
                    pos += skipped + 1;
                    if (m[0] == "\t") {
                        var tabSize = builder.cm.options.tabSize, tabWidth = tabSize - builder.col % tabSize;
                        content.appendChild(elt("span", spaceStr(tabWidth), "cm-tab"));
                        builder.col += tabWidth;
                    } else {
                        var token = elt("span", "\u2022", "cm-invalidchar");
                        token.title = "\\u" + m[0].charCodeAt(0).toString(16);
                        content.appendChild(token);
                        builder.col += 1;
                    }
                }
            }
            if (style || startStyle || endStyle || builder.measure) {
                var fullStyle = style || "";
                if (startStyle) fullStyle += startStyle;
                if (endStyle) fullStyle += endStyle;
                var token = elt("span", [content], fullStyle);
                if (title) token.title = title;
                return builder.pre.appendChild(token);
            }
            builder.pre.appendChild(content);
        }

        function buildTokenMeasure(builder, text, style, startStyle, endStyle) {
            var wrapping = builder.cm.options.lineWrapping;
            for (var i = 0; i < text.length; ++i) {
                var ch = text.charAt(i), start = i == 0;
                if (ch >= "\ud800" && ch < "\udbff" && i < text.length - 1) {
                    ch = text.slice(i, i + 2);
                    ++i;
                } else if (i && wrapping && spanAffectsWrapping(text, i)) {
                    builder.pre.appendChild(elt("wbr"));
                }
                var old = builder.measure[builder.pos];
                var span = builder.measure[builder.pos] =
                    buildToken(builder, ch, style,
                            start && startStyle, i == text.length - 1 && endStyle);
                if (old) span.leftSide = old.leftSide || old;
                // In IE single-space nodes wrap differently than spaces
                // embedded in larger text nodes, except when set to
                // white-space: normal (issue #1268).
                if (ie && wrapping && ch == " " && i && !/\s/.test(text.charAt(i - 1)) &&
                    i < text.length - 1 && !/\s/.test(text.charAt(i + 1)))
                    span.style.whiteSpace = "normal";
                builder.pos += ch.length;
            }
            if (text.length) builder.measuredSomething = true;
        }

        function buildTokenSplitSpaces(inner) {
            function split(old) {
                var out = " ";
                for (var i = 0; i < old.length - 2; ++i) out += i % 2 ? " " : "\u00a0";
                out += " ";
                return out;
            }
            return function(builder, text, style, startStyle, endStyle, title) {
                return inner(builder, text.replace(/ {3,}/, split), style, startStyle, endStyle, title);
            };
        }

        function buildCollapsedSpan(builder, size, marker, ignoreWidget) {
            var widget = !ignoreWidget && marker.replacedWith;
            if (widget) {
                if (builder.copyWidgets) widget = widget.cloneNode(true);
                builder.pre.appendChild(widget);
                if (builder.measure) {
                    if (size) {
                        builder.measure[builder.pos] = widget;
                    } else {
                        var elt = builder.measure[builder.pos] = zeroWidthElement(builder.cm.display.measure);
                        if (marker.type != "bookmark" || marker.insertLeft)
                            builder.pre.insertBefore(elt, widget);
                        else
                            builder.pre.appendChild(elt);
                    }
                    builder.measuredSomething = true;
                }
            }
            builder.pos += size;
        }

        // Outputs a number of spans to make up a line, taking highlighting
        // and marked text into account.
        function insertLineContent(line, builder, styles) {
            var spans = line.markedSpans, allText = line.text, at = 0;
            if (!spans) {
                for (var i = 1; i < styles.length; i+=2)
                    builder.addToken(builder, allText.slice(at, at = styles[i]), styleToClass(styles[i+1]));
                return;
            }

            var len = allText.length, pos = 0, i = 1, text = "", style;
            var nextChange = 0, spanStyle, spanEndStyle, spanStartStyle, title, collapsed;
            for (;;) {
                if (nextChange == pos) { // Update current marker set
                    spanStyle = spanEndStyle = spanStartStyle = title = "";
                    collapsed = null; nextChange = Infinity;
                    var foundBookmark = null;
                    for (var j = 0; j < spans.length; ++j) {
                        var sp = spans[j], m = sp.marker;
                        if (sp.from <= pos && (sp.to == null || sp.to > pos)) {
                            if (sp.to != null && nextChange > sp.to) { nextChange = sp.to; spanEndStyle = ""; }
                            if (m.className) spanStyle += " " + m.className;
                            if (m.startStyle && sp.from == pos) spanStartStyle += " " + m.startStyle;
                            if (m.endStyle && sp.to == nextChange) spanEndStyle += " " + m.endStyle;
                            if (m.title && !title) title = m.title;
                            if (m.collapsed && (!collapsed || collapsed.marker.size < m.size))
                                collapsed = sp;
                        } else if (sp.from > pos && nextChange > sp.from) {
                            nextChange = sp.from;
                        }
                        if (m.type == "bookmark" && sp.from == pos && m.replacedWith) foundBookmark = m;
                    }
                    if (collapsed && (collapsed.from || 0) == pos) {
                        buildCollapsedSpan(builder, (collapsed.to == null ? len : collapsed.to) - pos,
                            collapsed.marker, collapsed.from == null);
                        if (collapsed.to == null) return collapsed.marker.find();
                    }
                    if (foundBookmark && !collapsed) buildCollapsedSpan(builder, 0, foundBookmark);
                }
                if (pos >= len) break;

                var upto = Math.min(len, nextChange);
                while (true) {
                    if (text) {
                        var end = pos + text.length;
                        if (!collapsed) {
                            var tokenText = end > upto ? text.slice(0, upto - pos) : text;
                            builder.addToken(builder, tokenText, style ? style + spanStyle : spanStyle,
                                spanStartStyle, pos + tokenText.length == nextChange ? spanEndStyle : "", title);
                        }
                        if (end >= upto) {text = text.slice(upto - pos); pos = upto; break;}
                        pos = end;
                        spanStartStyle = "";
                    }
                    text = allText.slice(at, at = styles[i++]);
                    style = styleToClass(styles[i++]);
                }
            }
        }

        // DOCUMENT DATA STRUCTURE

        function updateDoc(doc, change, markedSpans, selAfter, estimateHeight) {
            function spansFor(n) {return markedSpans ? markedSpans[n] : null;}
            function update(line, text, spans) {
                updateLine(line, text, spans, estimateHeight);
                signalLater(line, "change", line, change);
            }

            var from = change.from, to = change.to, text = change.text;
            var firstLine = getLine(doc, from.line), lastLine = getLine(doc, to.line);
            var lastText = lst(text), lastSpans = spansFor(text.length - 1), nlines = to.line - from.line;

            // First adjust the line structure
            if (from.ch == 0 && to.ch == 0 && lastText == "") {
                // This is a whole-line replace. Treated specially to make
                // sure line objects move the way they are supposed to.
                for (var i = 0, e = text.length - 1, added = []; i < e; ++i)
                    added.push(new Line(text[i], spansFor(i), estimateHeight));
                update(lastLine, lastLine.text, lastSpans);
                if (nlines) doc.remove(from.line, nlines);
                if (added.length) doc.insert(from.line, added);
            } else if (firstLine == lastLine) {
                if (text.length == 1) {
                    update(firstLine, firstLine.text.slice(0, from.ch) + lastText + firstLine.text.slice(to.ch), lastSpans);
                } else {
                    for (var added = [], i = 1, e = text.length - 1; i < e; ++i)
                        added.push(new Line(text[i], spansFor(i), estimateHeight));
                    added.push(new Line(lastText + firstLine.text.slice(to.ch), lastSpans, estimateHeight));
                    update(firstLine, firstLine.text.slice(0, from.ch) + text[0], spansFor(0));
                    doc.insert(from.line + 1, added);
                }
            } else if (text.length == 1) {
                update(firstLine, firstLine.text.slice(0, from.ch) + text[0] + lastLine.text.slice(to.ch), spansFor(0));
                doc.remove(from.line + 1, nlines);
            } else {
                update(firstLine, firstLine.text.slice(0, from.ch) + text[0], spansFor(0));
                update(lastLine, lastText + lastLine.text.slice(to.ch), lastSpans);
                for (var i = 1, e = text.length - 1, added = []; i < e; ++i)
                    added.push(new Line(text[i], spansFor(i), estimateHeight));
                if (nlines > 1) doc.remove(from.line + 1, nlines - 1);
                doc.insert(from.line + 1, added);
            }

            signalLater(doc, "change", doc, change);
            setSelection(doc, selAfter.anchor, selAfter.head, null, true);
        }

        function LeafChunk(lines) {
            this.lines = lines;
            this.parent = null;
            for (var i = 0, e = lines.length, height = 0; i < e; ++i) {
                lines[i].parent = this;
                height += lines[i].height;
            }
            this.height = height;
        }

        LeafChunk.prototype = {
            chunkSize: function() { return this.lines.length; },
            removeInner: function(at, n) {
                for (var i = at, e = at + n; i < e; ++i) {
                    var line = this.lines[i];
                    this.height -= line.height;
                    cleanUpLine(line);
                    signalLater(line, "delete");
                }
                this.lines.splice(at, n);
            },
            collapse: function(lines) {
                lines.splice.apply(lines, [lines.length, 0].concat(this.lines));
            },
            insertInner: function(at, lines, height) {
                this.height += height;
                this.lines = this.lines.slice(0, at).concat(lines).concat(this.lines.slice(at));
                for (var i = 0, e = lines.length; i < e; ++i) lines[i].parent = this;
            },
            iterN: function(at, n, op) {
                for (var e = at + n; at < e; ++at)
                    if (op(this.lines[at])) return true;
            }
        };

        function BranchChunk(children) {
            this.children = children;
            var size = 0, height = 0;
            for (var i = 0, e = children.length; i < e; ++i) {
                var ch = children[i];
                size += ch.chunkSize(); height += ch.height;
                ch.parent = this;
            }
            this.size = size;
            this.height = height;
            this.parent = null;
        }

        BranchChunk.prototype = {
            chunkSize: function() { return this.size; },
            removeInner: function(at, n) {
                this.size -= n;
                for (var i = 0; i < this.children.length; ++i) {
                    var child = this.children[i], sz = child.chunkSize();
                    if (at < sz) {
                        var rm = Math.min(n, sz - at), oldHeight = child.height;
                        child.removeInner(at, rm);
                        this.height -= oldHeight - child.height;
                        if (sz == rm) { this.children.splice(i--, 1); child.parent = null; }
                        if ((n -= rm) == 0) break;
                        at = 0;
                    } else at -= sz;
                }
                if (this.size - n < 25) {
                    var lines = [];
                    this.collapse(lines);
                    this.children = [new LeafChunk(lines)];
                    this.children[0].parent = this;
                }
            },
            collapse: function(lines) {
                for (var i = 0, e = this.children.length; i < e; ++i) this.children[i].collapse(lines);
            },
            insertInner: function(at, lines, height) {
                this.size += lines.length;
                this.height += height;
                for (var i = 0, e = this.children.length; i < e; ++i) {
                    var child = this.children[i], sz = child.chunkSize();
                    if (at <= sz) {
                        child.insertInner(at, lines, height);
                        if (child.lines && child.lines.length > 50) {
                            while (child.lines.length > 50) {
                                var spilled = child.lines.splice(child.lines.length - 25, 25);
                                var newleaf = new LeafChunk(spilled);
                                child.height -= newleaf.height;
                                this.children.splice(i + 1, 0, newleaf);
                                newleaf.parent = this;
                            }
                            this.maybeSpill();
                        }
                        break;
                    }
                    at -= sz;
                }
            },
            maybeSpill: function() {
                if (this.children.length <= 10) return;
                var me = this;
                do {
                    var spilled = me.children.splice(me.children.length - 5, 5);
                    var sibling = new BranchChunk(spilled);
                    if (!me.parent) { // Become the parent node
                        var copy = new BranchChunk(me.children);
                        copy.parent = me;
                        me.children = [copy, sibling];
                        me = copy;
                    } else {
                        me.size -= sibling.size;
                        me.height -= sibling.height;
                        var myIndex = indexOf(me.parent.children, me);
                        me.parent.children.splice(myIndex + 1, 0, sibling);
                    }
                    sibling.parent = me.parent;
                } while (me.children.length > 10);
                me.parent.maybeSpill();
            },
            iterN: function(at, n, op) {
                for (var i = 0, e = this.children.length; i < e; ++i) {
                    var child = this.children[i], sz = child.chunkSize();
                    if (at < sz) {
                        var used = Math.min(n, sz - at);
                        if (child.iterN(at, used, op)) return true;
                        if ((n -= used) == 0) break;
                        at = 0;
                    } else at -= sz;
                }
            }
        };

        var nextDocId = 0;
        var Doc = CodeMirror.Doc = function(text, mode, firstLine) {
            if (!(this instanceof Doc)) return new Doc(text, mode, firstLine);
            if (firstLine == null) firstLine = 0;

            BranchChunk.call(this, [new LeafChunk([new Line("", null)])]);
            this.first = firstLine;
            this.scrollTop = this.scrollLeft = 0;
            this.cantEdit = false;
            this.history = makeHistory();
            this.cleanGeneration = 1;
            this.frontier = firstLine;
            var start = Pos(firstLine, 0);
            this.sel = {from: start, to: start, head: start, anchor: start, shift: false, extend: false, goalColumn: null};
            this.id = ++nextDocId;
            this.modeOption = mode;

            if (typeof text == "string") text = splitLines(text);
            updateDoc(this, {from: start, to: start, text: text}, null, {head: start, anchor: start});
        };

        Doc.prototype = createObj(BranchChunk.prototype, {
            constructor: Doc,
            iter: function(from, to, op) {
                if (op) this.iterN(from - this.first, to - from, op);
                else this.iterN(this.first, this.first + this.size, from);
            },

            insert: function(at, lines) {
                var height = 0;
                for (var i = 0, e = lines.length; i < e; ++i) height += lines[i].height;
                this.insertInner(at - this.first, lines, height);
            },
            remove: function(at, n) { this.removeInner(at - this.first, n); },

            getValue: function(lineSep) {
                var lines = getLines(this, this.first, this.first + this.size);
                if (lineSep === false) return lines;
                return lines.join(lineSep || "\n");
            },
            setValue: function(code) {
                var top = Pos(this.first, 0), last = this.first + this.size - 1;
                makeChange(this, {from: top, to: Pos(last, getLine(this, last).text.length),
                        text: splitLines(code), origin: "setValue"},
                    {head: top, anchor: top}, true);
            },
            replaceRange: function(code, from, to, origin) {
                from = clipPos(this, from);
                to = to ? clipPos(this, to) : from;
                replaceRange(this, code, from, to, origin);
            },
            getRange: function(from, to, lineSep) {
                var lines = getBetween(this, clipPos(this, from), clipPos(this, to));
                if (lineSep === false) return lines;
                return lines.join(lineSep || "\n");
            },

            getLine: function(line) {var l = this.getLineHandle(line); return l && l.text;},
            setLine: function(line, text) {
                if (isLine(this, line))
                    replaceRange(this, text, Pos(line, 0), clipPos(this, Pos(line)));
            },
            removeLine: function(line) {
                if (line) replaceRange(this, "", clipPos(this, Pos(line - 1)), clipPos(this, Pos(line)));
                else replaceRange(this, "", Pos(0, 0), clipPos(this, Pos(1, 0)));
            },

            getLineHandle: function(line) {if (isLine(this, line)) return getLine(this, line);},
            getLineNumber: function(line) {return lineNo(line);},

            getLineHandleVisualStart: function(line) {
                if (typeof line == "number") line = getLine(this, line);
                return visualLine(this, line);
            },

            lineCount: function() {return this.size;},
            firstLine: function() {return this.first;},
            lastLine: function() {return this.first + this.size - 1;},

            clipPos: function(pos) {return clipPos(this, pos);},

            getCursor: function(start) {
                var sel = this.sel, pos;
                if (start == null || start == "head") pos = sel.head;
                else if (start == "anchor") pos = sel.anchor;
                else if (start == "end" || start === false) pos = sel.to;
                else pos = sel.from;
                return copyPos(pos);
            },
            somethingSelected: function() {return !posEq(this.sel.head, this.sel.anchor);},

            setCursor: docOperation(function(line, ch, extend) {
                var pos = clipPos(this, typeof line == "number" ? Pos(line, ch || 0) : line);
                if (extend) extendSelection(this, pos);
                else setSelection(this, pos, pos);
            }),
            setSelection: docOperation(function(anchor, head) {
                setSelection(this, clipPos(this, anchor), clipPos(this, head || anchor));
            }),
            extendSelection: docOperation(function(from, to) {
                extendSelection(this, clipPos(this, from), to && clipPos(this, to));
            }),

            getSelection: function(lineSep) {return this.getRange(this.sel.from, this.sel.to, lineSep);},
            replaceSelection: function(code, collapse, origin) {
                makeChange(this, {from: this.sel.from, to: this.sel.to, text: splitLines(code), origin: origin}, collapse || "around");
            },
            undo: docOperation(function() {makeChangeFromHistory(this, "undo");}),
            redo: docOperation(function() {makeChangeFromHistory(this, "redo");}),

            setExtending: function(val) {this.sel.extend = val;},

            historySize: function() {
                var hist = this.history;
                return {undo: hist.done.length, redo: hist.undone.length};
            },
            clearHistory: function() {this.history = makeHistory(this.history.maxGeneration);},

            markClean: function() {
                this.cleanGeneration = this.changeGeneration();
            },
            changeGeneration: function() {
                this.history.lastOp = this.history.lastOrigin = null;
                return this.history.generation;
            },
            isClean: function (gen) {
                return this.history.generation == (gen || this.cleanGeneration);
            },

            getHistory: function() {
                return {done: copyHistoryArray(this.history.done),
                    undone: copyHistoryArray(this.history.undone)};
            },
            setHistory: function(histData) {
                var hist = this.history = makeHistory(this.history.maxGeneration);
                hist.done = histData.done.slice(0);
                hist.undone = histData.undone.slice(0);
            },

            markText: function(from, to, options) {
                return markText(this, clipPos(this, from), clipPos(this, to), options, "range");
            },
            setBookmark: function(pos, options) {
                var realOpts = {replacedWith: options && (options.nodeType == null ? options.widget : options),
                    insertLeft: options && options.insertLeft};
                pos = clipPos(this, pos);
                return markText(this, pos, pos, realOpts, "bookmark");
            },
            findMarksAt: function(pos) {
                pos = clipPos(this, pos);
                var markers = [], spans = getLine(this, pos.line).markedSpans;
                if (spans) for (var i = 0; i < spans.length; ++i) {
                    var span = spans[i];
                    if ((span.from == null || span.from <= pos.ch) &&
                        (span.to == null || span.to >= pos.ch))
                        markers.push(span.marker.parent || span.marker);
                }
                return markers;
            },
            getAllMarks: function() {
                var markers = [];
                this.iter(function(line) {
                    var sps = line.markedSpans;
                    if (sps) for (var i = 0; i < sps.length; ++i)
                        if (sps[i].from != null) markers.push(sps[i].marker);
                });
                return markers;
            },

            posFromIndex: function(off) {
                var ch, lineNo = this.first;
                this.iter(function(line) {
                    var sz = line.text.length + 1;
                    if (sz > off) { ch = off; return true; }
                    off -= sz;
                    ++lineNo;
                });
                return clipPos(this, Pos(lineNo, ch));
            },
            indexFromPos: function (coords) {
                coords = clipPos(this, coords);
                var index = coords.ch;
                if (coords.line < this.first || coords.ch < 0) return 0;
                this.iter(this.first, coords.line, function (line) {
                    index += line.text.length + 1;
                });
                return index;
            },

            copy: function(copyHistory) {
                var doc = new Doc(getLines(this, this.first, this.first + this.size), this.modeOption, this.first);
                doc.scrollTop = this.scrollTop; doc.scrollLeft = this.scrollLeft;
                doc.sel = {from: this.sel.from, to: this.sel.to, head: this.sel.head, anchor: this.sel.anchor,
                    shift: this.sel.shift, extend: false, goalColumn: this.sel.goalColumn};
                if (copyHistory) {
                    doc.history.undoDepth = this.history.undoDepth;
                    doc.setHistory(this.getHistory());
                }
                return doc;
            },

            linkedDoc: function(options) {
                if (!options) options = {};
                var from = this.first, to = this.first + this.size;
                if (options.from != null && options.from > from) from = options.from;
                if (options.to != null && options.to < to) to = options.to;
                var copy = new Doc(getLines(this, from, to), options.mode || this.modeOption, from);
                if (options.sharedHist) copy.history = this.history;
                (this.linked || (this.linked = [])).push({doc: copy, sharedHist: options.sharedHist});
                copy.linked = [{doc: this, isParent: true, sharedHist: options.sharedHist}];
                return copy;
            },
            unlinkDoc: function(other) {
                if (other instanceof CodeMirror) other = other.doc;
                if (this.linked) for (var i = 0; i < this.linked.length; ++i) {
                    var link = this.linked[i];
                    if (link.doc != other) continue;
                    this.linked.splice(i, 1);
                    other.unlinkDoc(this);
                    break;
                }
                // If the histories were shared, split them again
                if (other.history == this.history) {
                    var splitIds = [other.id];
                    linkedDocs(other, function(doc) {splitIds.push(doc.id);}, true);
                    other.history = makeHistory();
                    other.history.done = copyHistoryArray(this.history.done, splitIds);
                    other.history.undone = copyHistoryArray(this.history.undone, splitIds);
                }
            },
            iterLinkedDocs: function(f) {linkedDocs(this, f);},

            getMode: function() {return this.mode;},
            getEditor: function() {return this.cm;}
        });

        Doc.prototype.eachLine = Doc.prototype.iter;

        // The Doc methods that should be available on CodeMirror instances
        var dontDelegate = "iter insert remove copy getEditor".split(" ");
        for (var prop in Doc.prototype) if (Doc.prototype.hasOwnProperty(prop) && indexOf(dontDelegate, prop) < 0)
            CodeMirror.prototype[prop] = (function(method) {
                return function() {return method.apply(this.doc, arguments);};
            })(Doc.prototype[prop]);

        eventMixin(Doc);

        function linkedDocs(doc, f, sharedHistOnly) {
            function propagate(doc, skip, sharedHist) {
                if (doc.linked) for (var i = 0; i < doc.linked.length; ++i) {
                    var rel = doc.linked[i];
                    if (rel.doc == skip) continue;
                    var shared = sharedHist && rel.sharedHist;
                    if (sharedHistOnly && !shared) continue;
                    f(rel.doc, shared);
                    propagate(rel.doc, doc, shared);
                }
            }
            propagate(doc, null, true);
        }

        function attachDoc(cm, doc) {
            if (doc.cm) throw new Error("This document is already in use.");
            cm.doc = doc;
            doc.cm = cm;
            estimateLineHeights(cm);
            loadMode(cm);
            if (!cm.options.lineWrapping) computeMaxLength(cm);
            cm.options.mode = doc.modeOption;
            regChange(cm);
        }

        // LINE UTILITIES

        function getLine(chunk, n) {
            n -= chunk.first;
            while (!chunk.lines) {
                for (var i = 0;; ++i) {
                    var child = chunk.children[i], sz = child.chunkSize();
                    if (n < sz) { chunk = child; break; }
                    n -= sz;
                }
            }
            return chunk.lines[n];
        }

        function getBetween(doc, start, end) {
            var out = [], n = start.line;
            doc.iter(start.line, end.line + 1, function(line) {
                var text = line.text;
                if (n == end.line) text = text.slice(0, end.ch);
                if (n == start.line) text = text.slice(start.ch);
                out.push(text);
                ++n;
            });
            return out;
        }
        function getLines(doc, from, to) {
            var out = [];
            doc.iter(from, to, function(line) { out.push(line.text); });
            return out;
        }

        function updateLineHeight(line, height) {
            var diff = height - line.height;
            for (var n = line; n; n = n.parent) n.height += diff;
        }

        function lineNo(line) {
            if (line.parent == null) return null;
            var cur = line.parent, no = indexOf(cur.lines, line);
            for (var chunk = cur.parent; chunk; cur = chunk, chunk = chunk.parent) {
                for (var i = 0;; ++i) {
                    if (chunk.children[i] == cur) break;
                    no += chunk.children[i].chunkSize();
                }
            }
            return no + cur.first;
        }

        function lineAtHeight(chunk, h) {
            var n = chunk.first;
            outer: do {
                for (var i = 0, e = chunk.children.length; i < e; ++i) {
                    var child = chunk.children[i], ch = child.height;
                    if (h < ch) { chunk = child; continue outer; }
                    h -= ch;
                    n += child.chunkSize();
                }
                return n;
            } while (!chunk.lines);
            for (var i = 0, e = chunk.lines.length; i < e; ++i) {
                var line = chunk.lines[i], lh = line.height;
                if (h < lh) break;
                h -= lh;
            }
            return n + i;
        }

        function heightAtLine(cm, lineObj) {
            lineObj = visualLine(cm.doc, lineObj);

            var h = 0, chunk = lineObj.parent;
            for (var i = 0; i < chunk.lines.length; ++i) {
                var line = chunk.lines[i];
                if (line == lineObj) break;
                else h += line.height;
            }
            for (var p = chunk.parent; p; chunk = p, p = chunk.parent) {
                for (var i = 0; i < p.children.length; ++i) {
                    var cur = p.children[i];
                    if (cur == chunk) break;
                    else h += cur.height;
                }
            }
            return h;
        }

        function getOrder(line) {
            var order = line.order;
            if (order == null) order = line.order = bidiOrdering(line.text);
            return order;
        }

        // HISTORY

        function makeHistory(startGen) {
            return {
                // Arrays of history events. Doing something adds an event to
                // done and clears undo. Undoing moves events from done to
                // undone, redoing moves them in the other direction.
                done: [], undone: [], undoDepth: Infinity,
                // Used to track when changes can be merged into a single undo
                // event
                lastTime: 0, lastOp: null, lastOrigin: null,
                // Used by the isClean() method
                generation: startGen || 1, maxGeneration: startGen || 1
            };
        }

        function attachLocalSpans(doc, change, from, to) {
            var existing = change["spans_" + doc.id], n = 0;
            doc.iter(Math.max(doc.first, from), Math.min(doc.first + doc.size, to), function(line) {
                if (line.markedSpans)
                    (existing || (existing = change["spans_" + doc.id] = {}))[n] = line.markedSpans;
                ++n;
            });
        }

        function historyChangeFromChange(doc, change) {
            var from = { line: change.from.line, ch: change.from.ch };
            var histChange = {from: from, to: changeEnd(change), text: getBetween(doc, change.from, change.to)};
            attachLocalSpans(doc, histChange, change.from.line, change.to.line + 1);
            linkedDocs(doc, function(doc) {attachLocalSpans(doc, histChange, change.from.line, change.to.line + 1);}, true);
            return histChange;
        }

        function addToHistory(doc, change, selAfter, opId) {
            var hist = doc.history;
            hist.undone.length = 0;
            var time = +new Date, cur = lst(hist.done);

            if (cur &&
                (hist.lastOp == opId ||
                    hist.lastOrigin == change.origin && change.origin &&
                    ((change.origin.charAt(0) == "+" && doc.cm && hist.lastTime > time - doc.cm.options.historyEventDelay) ||
                        change.origin.charAt(0) == "*"))) {
                // Merge this change into the last event
                var last = lst(cur.changes);
                if (posEq(change.from, change.to) && posEq(change.from, last.to)) {
                    // Optimized case for simple insertion -- don't want to add
                    // new changesets for every character typed
                    last.to = changeEnd(change);
                } else {
                    // Add new sub-event
                    cur.changes.push(historyChangeFromChange(doc, change));
                }
                cur.anchorAfter = selAfter.anchor; cur.headAfter = selAfter.head;
            } else {
                // Can not be merged, start a new event.
                cur = {changes: [historyChangeFromChange(doc, change)],
                    generation: hist.generation,
                    anchorBefore: doc.sel.anchor, headBefore: doc.sel.head,
                    anchorAfter: selAfter.anchor, headAfter: selAfter.head};
                hist.done.push(cur);
                hist.generation = ++hist.maxGeneration;
                while (hist.done.length > hist.undoDepth)
                    hist.done.shift();
            }
            hist.lastTime = time;
            hist.lastOp = opId;
            hist.lastOrigin = change.origin;
        }

        function removeClearedSpans(spans) {
            if (!spans) return null;
            for (var i = 0, out; i < spans.length; ++i) {
                if (spans[i].marker.explicitlyCleared) { if (!out) out = spans.slice(0, i); }
                else if (out) out.push(spans[i]);
            }
            return !out ? spans : out.length ? out : null;
        }

        function getOldSpans(doc, change) {
            var found = change["spans_" + doc.id];
            if (!found) return null;
            for (var i = 0, nw = []; i < change.text.length; ++i)
                nw.push(removeClearedSpans(found[i]));
            return nw;
        }

        // Used both to provide a JSON-safe object in .getHistory, and, when
        // detaching a document, to split the history in two
        function copyHistoryArray(events, newGroup) {
            for (var i = 0, copy = []; i < events.length; ++i) {
                var event = events[i], changes = event.changes, newChanges = [];
                copy.push({changes: newChanges, anchorBefore: event.anchorBefore, headBefore: event.headBefore,
                    anchorAfter: event.anchorAfter, headAfter: event.headAfter});
                for (var j = 0; j < changes.length; ++j) {
                    var change = changes[j], m;
                    newChanges.push({from: change.from, to: change.to, text: change.text});
                    if (newGroup) for (var prop in change) if (m = prop.match(/^spans_(\d+)$/)) {
                        if (indexOf(newGroup, Number(m[1])) > -1) {
                            lst(newChanges)[prop] = change[prop];
                            delete change[prop];
                        }
                    }
                }
            }
            return copy;
        }

        // Rebasing/resetting history to deal with externally-sourced changes

        function rebaseHistSel(pos, from, to, diff) {
            if (to < pos.line) {
                pos.line += diff;
            } else if (from < pos.line) {
                pos.line = from;
                pos.ch = 0;
            }
        }

        // Tries to rebase an array of history events given a change in the
        // document. If the change touches the same lines as the event, the
        // event, and everything 'behind' it, is discarded. If the change is
        // before the event, the event's positions are updated. Uses a
        // copy-on-write scheme for the positions, to avoid having to
        // reallocate them all on every rebase, but also avoid problems with
        // shared position objects being unsafely updated.
        function rebaseHistArray(array, from, to, diff) {
            for (var i = 0; i < array.length; ++i) {
                var sub = array[i], ok = true;
                for (var j = 0; j < sub.changes.length; ++j) {
                    var cur = sub.changes[j];
                    if (!sub.copied) { cur.from = copyPos(cur.from); cur.to = copyPos(cur.to); }
                    if (to < cur.from.line) {
                        cur.from.line += diff;
                        cur.to.line += diff;
                    } else if (from <= cur.to.line) {
                        ok = false;
                        break;
                    }
                }
                if (!sub.copied) {
                    sub.anchorBefore = copyPos(sub.anchorBefore); sub.headBefore = copyPos(sub.headBefore);
                    sub.anchorAfter = copyPos(sub.anchorAfter); sub.readAfter = copyPos(sub.headAfter);
                    sub.copied = true;
                }
                if (!ok) {
                    array.splice(0, i + 1);
                    i = 0;
                } else {
                    rebaseHistSel(sub.anchorBefore); rebaseHistSel(sub.headBefore);
                    rebaseHistSel(sub.anchorAfter); rebaseHistSel(sub.headAfter);
                }
            }
        }

        function rebaseHist(hist, change) {
            var from = change.from.line, to = change.to.line, diff = change.text.length - (to - from) - 1;
            rebaseHistArray(hist.done, from, to, diff);
            rebaseHistArray(hist.undone, from, to, diff);
        }

        // EVENT OPERATORS

        function stopMethod() {e_stop(this);}
        // Ensure an event has a stop method.
        function addStop(event) {
            if (!event.stop) event.stop = stopMethod;
            return event;
        }

        function e_preventDefault(e) {
            if (e.preventDefault) e.preventDefault();
            else e.returnValue = false;
        }
        function e_stopPropagation(e) {
            if (e.stopPropagation) e.stopPropagation();
            else e.cancelBubble = true;
        }
        function e_defaultPrevented(e) {
            return e.defaultPrevented != null ? e.defaultPrevented : e.returnValue == false;
        }
        function e_stop(e) {e_preventDefault(e); e_stopPropagation(e);}
        CodeMirror.e_stop = e_stop;
        CodeMirror.e_preventDefault = e_preventDefault;
        CodeMirror.e_stopPropagation = e_stopPropagation;

        function e_target(e) {return e.target || e.srcElement;}
        function e_button(e) {
            var b = e.which;
            if (b == null) {
                if (e.button & 1) b = 1;
                else if (e.button & 2) b = 3;
                else if (e.button & 4) b = 2;
            }
            if (mac && e.ctrlKey && b == 1) b = 3;
            return b;
        }

        // EVENT HANDLING

        function on(emitter, type, f) {
            if (emitter.addEventListener)
                emitter.addEventListener(type, f, false);
            else if (emitter.attachEvent)
                emitter.attachEvent("on" + type, f);
            else {
                var map = emitter._handlers || (emitter._handlers = {});
                var arr = map[type] || (map[type] = []);
                arr.push(f);
            }
        }

        function off(emitter, type, f) {
            if (emitter.removeEventListener)
                emitter.removeEventListener(type, f, false);
            else if (emitter.detachEvent)
                emitter.detachEvent("on" + type, f);
            else {
                var arr = emitter._handlers && emitter._handlers[type];
                if (!arr) return;
                for (var i = 0; i < arr.length; ++i)
                    if (arr[i] == f) { arr.splice(i, 1); break; }
            }
        }

        function signal(emitter, type /*, values...*/) {
            var arr = emitter._handlers && emitter._handlers[type];
            if (!arr) return;
            var args = Array.prototype.slice.call(arguments, 2);
            for (var i = 0; i < arr.length; ++i) arr[i].apply(null, args);
        }

        var delayedCallbacks, delayedCallbackDepth = 0;
        function signalLater(emitter, type /*, values...*/) {
            var arr = emitter._handlers && emitter._handlers[type];
            if (!arr) return;
            var args = Array.prototype.slice.call(arguments, 2);
            if (!delayedCallbacks) {
                ++delayedCallbackDepth;
                delayedCallbacks = [];
                setTimeout(fireDelayed, 0);
            }
            function bnd(f) {return function(){f.apply(null, args);};};
            for (var i = 0; i < arr.length; ++i)
                delayedCallbacks.push(bnd(arr[i]));
        }

        function signalDOMEvent(cm, e, override) {
            signal(cm, override || e.type, cm, e);
            return e_defaultPrevented(e) || e.codemirrorIgnore;
        }

        function fireDelayed() {
            --delayedCallbackDepth;
            var delayed = delayedCallbacks;
            delayedCallbacks = null;
            for (var i = 0; i < delayed.length; ++i) delayed[i]();
        }

        function hasHandler(emitter, type) {
            var arr = emitter._handlers && emitter._handlers[type];
            return arr && arr.length > 0;
        }

        CodeMirror.on = on; CodeMirror.off = off; CodeMirror.signal = signal;

        function eventMixin(ctor) {
            ctor.prototype.on = function(type, f) {on(this, type, f);};
            ctor.prototype.off = function(type, f) {off(this, type, f);};
        }

        // MISC UTILITIES

        // Number of pixels added to scroller and sizer to hide scrollbar
        var scrollerCutOff = 30;

        // Returned or thrown by various protocols to signal 'I'm not
        // handling this'.
        var Pass = CodeMirror.Pass = {toString: function(){return "CodeMirror.Pass";}};

        function Delayed() {this.id = null;}
        Delayed.prototype = {set: function(ms, f) {clearTimeout(this.id); this.id = setTimeout(f, ms);}};

        // Counts the column offset in a string, taking tabs into account.
        // Used mostly to find indentation.
        function countColumn(string, end, tabSize, startIndex, startValue) {
            if (end == null) {
                end = string.search(/[^\s\u00a0]/);
                if (end == -1) end = string.length;
            }
            for (var i = startIndex || 0, n = startValue || 0; i < end; ++i) {
                if (string.charAt(i) == "\t") n += tabSize - (n % tabSize);
                else ++n;
            }
            return n;
        }
        CodeMirror.countColumn = countColumn;

        var spaceStrs = [""];
        function spaceStr(n) {
            while (spaceStrs.length <= n)
                spaceStrs.push(lst(spaceStrs) + " ");
            return spaceStrs[n];
        }

        function lst(arr) { return arr[arr.length-1]; }

        function selectInput(node) {
            if (ios) { // Mobile Safari apparently has a bug where select() is broken.
                node.selectionStart = 0;
                node.selectionEnd = node.value.length;
            } else {
                // Suppress mysterious IE10 errors
                try { node.select(); }
                catch(_e) {}
            }
        }

        function indexOf(collection, elt) {
            if (collection.indexOf) return collection.indexOf(elt);
            for (var i = 0, e = collection.length; i < e; ++i)
                if (collection[i] == elt) return i;
            return -1;
        }

        function createObj(base, props) {
            function Obj() {}
            Obj.prototype = base;
            var inst = new Obj();
            if (props) copyObj(props, inst);
            return inst;
        }

        function copyObj(obj, target) {
            if (!target) target = {};
            for (var prop in obj) if (obj.hasOwnProperty(prop)) target[prop] = obj[prop];
            return target;
        }

        function emptyArray(size) {
            for (var a = [], i = 0; i < size; ++i) a.push(undefined);
            return a;
        }

        function bind(f) {
            var args = Array.prototype.slice.call(arguments, 1);
            return function(){return f.apply(null, args);};
        }

        var nonASCIISingleCaseWordChar = /[\u3040-\u309f\u30a0-\u30ff\u3400-\u4db5\u4e00-\u9fcc\uac00-\ud7af]/;
        function isWordChar(ch) {
            return /\w/.test(ch) || ch > "\x80" &&
                (ch.toUpperCase() != ch.toLowerCase() || nonASCIISingleCaseWordChar.test(ch));
        }

        function isEmpty(obj) {
            for (var n in obj) if (obj.hasOwnProperty(n) && obj[n]) return false;
            return true;
        }

        var isExtendingChar = /[\u0300-\u036F\u0483-\u0487\u0488-\u0489\u0591-\u05BD\u05BF\u05C1-\u05C2\u05C4-\u05C5\u05C7\u0610-\u061A\u064B-\u065F\u0670\u06D6-\u06DC\u06DF-\u06E4\u06E7-\u06E8\u06EA-\u06ED\uA66F\uA670-\uA672\uA674-\uA67D\uA69F\udc00-\udfff]/;

        // DOM UTILITIES

        function elt(tag, content, className, style) {
            var e = document.createElement(tag);
            if (className) e.className = className;
            if (style) e.style.cssText = style;
            if (typeof content == "string") setTextContent(e, content);
            else if (content) for (var i = 0; i < content.length; ++i) e.appendChild(content[i]);
            return e;
        }

        function removeChildren(e) {
            for (var count = e.childNodes.length; count > 0; --count)
                e.removeChild(e.firstChild);
            return e;
        }

        function removeChildrenAndAdd(parent, e) {
            return removeChildren(parent).appendChild(e);
        }

        function setTextContent(e, str) {
            if (ie_lt9) {
                e.innerHTML = "";
                e.appendChild(document.createTextNode(str));
            } else e.textContent = str;
        }

        function getRect(node) {
            return node.getBoundingClientRect();
        }
        CodeMirror.replaceGetRect = function(f) { getRect = f; };

        // FEATURE DETECTION

        // Detect drag-and-drop
        var dragAndDrop = function() {
            // There is *some* kind of drag-and-drop support in IE6-8, but I
            // couldn't get it to work yet.
            if (ie_lt9) return false;
            var div = elt('div');
            return "draggable" in div || "dragDrop" in div;
        }();

        // For a reason I have yet to figure out, some browsers disallow
        // word wrapping between certain characters *only* if a new inline
        // element is started between them. This makes it hard to reliably
        // measure the position of things, since that requires inserting an
        // extra span. This terribly fragile set of tests matches the
        // character combinations that suffer from this phenomenon on the
        // various browsers.
        function spanAffectsWrapping() { return false; }
        if (gecko) // Only for "$'"
            spanAffectsWrapping = function(str, i) {
                return str.charCodeAt(i - 1) == 36 && str.charCodeAt(i) == 39;
            };
        else if (safari && !/Version\/([6-9]|\d\d)\b/.test(navigator.userAgent))
            spanAffectsWrapping = function(str, i) {
                return /\-[^ \-?]|\?[^ !\'\"\),.\-\/:;\?\]\}]/.test(str.slice(i - 1, i + 1));
            };
        else if (webkit && !/Chrome\/(?:29|[3-9]\d|\d\d\d)\./.test(navigator.userAgent))
            spanAffectsWrapping = function(str, i) {
                if (i > 1 && str.charCodeAt(i - 1) == 45) {
                    if (/\w/.test(str.charAt(i - 2)) && /[^\-?\.]/.test(str.charAt(i))) return true;
                    if (i > 2 && /[\d\.,]/.test(str.charAt(i - 2)) && /[\d\.,]/.test(str.charAt(i))) return false;
                }
                return /[~!#%&*)=+}\]|\"\.>,:;][({[<]|-[^\-?\.\u2010-\u201f\u2026]|\?[\w~`@#$%\^&*(_=+{[|><]|…[\w~`@#$%\^&*(_=+{[><]/.test(str.slice(i - 1, i + 1));
            };

        var knownScrollbarWidth;
        function scrollbarWidth(measure) {
            if (knownScrollbarWidth != null) return knownScrollbarWidth;
            var test = elt("div", null, null, "width: 50px; height: 50px; overflow-x: scroll");
            removeChildrenAndAdd(measure, test);
            if (test.offsetWidth)
                knownScrollbarWidth = test.offsetHeight - test.clientHeight;
            return knownScrollbarWidth || 0;
        }

        var zwspSupported;
        function zeroWidthElement(measure) {
            if (zwspSupported == null) {
                var test = elt("span", "\u200b");
                removeChildrenAndAdd(measure, elt("span", [test, document.createTextNode("x")]));
                if (measure.firstChild.offsetHeight != 0)
                    zwspSupported = test.offsetWidth <= 1 && test.offsetHeight > 2 && !ie_lt8;
            }
            if (zwspSupported) return elt("span", "\u200b");
            else return elt("span", "\u00a0", null, "display: inline-block; width: 1px; margin-right: -1px");
        }

        // See if "".split is the broken IE version, if so, provide an
        // alternative way to split lines.
        var splitLines = "\n\nb".split(/\n/).length != 3 ? function(string) {
            var pos = 0, result = [], l = string.length;
            while (pos <= l) {
                var nl = string.indexOf("\n", pos);
                if (nl == -1) nl = string.length;
                var line = string.slice(pos, string.charAt(nl - 1) == "\r" ? nl - 1 : nl);
                var rt = line.indexOf("\r");
                if (rt != -1) {
                    result.push(line.slice(0, rt));
                    pos += rt + 1;
                } else {
                    result.push(line);
                    pos = nl + 1;
                }
            }
            return result;
        } : function(string){return string.split(/\r\n?|\n/);};
        CodeMirror.splitLines = splitLines;

        var hasSelection = window.getSelection ? function(te) {
            try { return te.selectionStart != te.selectionEnd; }
            catch(e) { return false; }
        } : function(te) {
            try {var range = te.ownerDocument.selection.createRange();}
            catch(e) {}
            if (!range || range.parentElement() != te) return false;
            return range.compareEndPoints("StartToEnd", range) != 0;
        };

        var hasCopyEvent = (function() {
            var e = elt("div");
            if ("oncopy" in e) return true;
            e.setAttribute("oncopy", "return;");
            return typeof e.oncopy == 'function';
        })();

        // KEY NAMING

        var keyNames = {3: "Enter", 8: "Backspace", 9: "Tab", 13: "Enter", 16: "Shift", 17: "Ctrl", 18: "Alt",
            19: "Pause", 20: "CapsLock", 27: "Esc", 32: "Space", 33: "PageUp", 34: "PageDown", 35: "End",
            36: "Home", 37: "Left", 38: "Up", 39: "Right", 40: "Down", 44: "PrintScrn", 45: "Insert",
            46: "Delete", 59: ";", 91: "Mod", 92: "Mod", 93: "Mod", 109: "-", 107: "=", 127: "Delete",
            186: ";", 187: "=", 188: ",", 189: "-", 190: ".", 191: "/", 192: "`", 219: "[", 220: "\\",
            221: "]", 222: "'", 63276: "PageUp", 63277: "PageDown", 63275: "End", 63273: "Home",
            63234: "Left", 63232: "Up", 63235: "Right", 63233: "Down", 63302: "Insert", 63272: "Delete"};
        CodeMirror.keyNames = keyNames;
        (function() {
            // Number keys
            for (var i = 0; i < 10; i++) keyNames[i + 48] = String(i);
            // Alphabetic keys
            for (var i = 65; i <= 90; i++) keyNames[i] = String.fromCharCode(i);
            // Function keys
            for (var i = 1; i <= 12; i++) keyNames[i + 111] = keyNames[i + 63235] = "F" + i;
        })();

        // BIDI HELPERS

        function iterateBidiSections(order, from, to, f) {
            if (!order) return f(from, to, "ltr");
            var found = false;
            for (var i = 0; i < order.length; ++i) {
                var part = order[i];
                if (part.from < to && part.to > from || from == to && part.to == from) {
                    f(Math.max(part.from, from), Math.min(part.to, to), part.level == 1 ? "rtl" : "ltr");
                    found = true;
                }
            }
            if (!found) f(from, to, "ltr");
        }

        function bidiLeft(part) { return part.level % 2 ? part.to : part.from; }
        function bidiRight(part) { return part.level % 2 ? part.from : part.to; }

        function lineLeft(line) { var order = getOrder(line); return order ? bidiLeft(order[0]) : 0; }
        function lineRight(line) {
            var order = getOrder(line);
            if (!order) return line.text.length;
            return bidiRight(lst(order));
        }

        function lineStart(cm, lineN) {
            var line = getLine(cm.doc, lineN);
            var visual = visualLine(cm.doc, line);
            if (visual != line) lineN = lineNo(visual);
            var order = getOrder(visual);
            var ch = !order ? 0 : order[0].level % 2 ? lineRight(visual) : lineLeft(visual);
            return Pos(lineN, ch);
        }
        function lineEnd(cm, lineN) {
            var merged, line;
            while (merged = collapsedSpanAtEnd(line = getLine(cm.doc, lineN)))
                lineN = merged.find().to.line;
            var order = getOrder(line);
            var ch = !order ? line.text.length : order[0].level % 2 ? lineLeft(line) : lineRight(line);
            return Pos(lineN, ch);
        }

        function compareBidiLevel(order, a, b) {
            var linedir = order[0].level;
            if (a == linedir) return true;
            if (b == linedir) return false;
            return a < b;
        }
        var bidiOther;
        function getBidiPartAt(order, pos) {
            for (var i = 0, found; i < order.length; ++i) {
                var cur = order[i];
                if (cur.from < pos && cur.to > pos) { bidiOther = null; return i; }
                if (cur.from == pos || cur.to == pos) {
                    if (found == null) {
                        found = i;
                    } else if (compareBidiLevel(order, cur.level, order[found].level)) {
                        bidiOther = found;
                        return i;
                    } else {
                        bidiOther = i;
                        return found;
                    }
                }
            }
            bidiOther = null;
            return found;
        }

        function moveInLine(line, pos, dir, byUnit) {
            if (!byUnit) return pos + dir;
            do pos += dir;
            while (pos > 0 && isExtendingChar.test(line.text.charAt(pos)));
            return pos;
        }

        // This is somewhat involved. It is needed in order to move
        // 'visually' through bi-directional text -- i.e., pressing left
        // should make the cursor go left, even when in RTL text. The
        // tricky part is the 'jumps', where RTL and LTR text touch each
        // other. This often requires the cursor offset to move more than
        // one unit, in order to visually move one unit.
        function moveVisually(line, start, dir, byUnit) {
            var bidi = getOrder(line);
            if (!bidi) return moveLogically(line, start, dir, byUnit);
            var pos = getBidiPartAt(bidi, start), part = bidi[pos];
            var target = moveInLine(line, start, part.level % 2 ? -dir : dir, byUnit);

            for (;;) {
                if (target > part.from && target < part.to) return target;
                if (target == part.from || target == part.to) {
                    if (getBidiPartAt(bidi, target) == pos) return target;
                    part = bidi[pos += dir];
                    return (dir > 0) == part.level % 2 ? part.to : part.from;
                } else {
                    part = bidi[pos += dir];
                    if (!part) return null;
                    if ((dir > 0) == part.level % 2)
                        target = moveInLine(line, part.to, -1, byUnit);
                    else
                        target = moveInLine(line, part.from, 1, byUnit);
                }
            }
        }

        function moveLogically(line, start, dir, byUnit) {
            var target = start + dir;
            if (byUnit) while (target > 0 && isExtendingChar.test(line.text.charAt(target))) target += dir;
            return target < 0 || target > line.text.length ? null : target;
        }

        // Bidirectional ordering algorithm
        // See http://unicode.org/reports/tr9/tr9-13.html for the algorithm
        // that this (partially) implements.

        // One-char codes used for character types:
        // L (L):   Left-to-Right
        // R (R):   Right-to-Left
        // r (AL):  Right-to-Left Arabic
        // 1 (EN):  European Number
        // + (ES):  European Number Separator
        // % (ET):  European Number Terminator
        // n (AN):  Arabic Number
        // , (CS):  Common Number Separator
        // m (NSM): Non-Spacing Mark
        // b (BN):  Boundary Neutral
        // s (B):   Paragraph Separator
        // t (S):   Segment Separator
        // w (WS):  Whitespace
        // N (ON):  Other Neutrals

        // Returns null if characters are ordered as they appear
        // (left-to-right), or an array of sections ({from, to, level}
        // objects) in the order in which they occur visually.
        var bidiOrdering = (function() {
            // Character types for codepoints 0 to 0xff
            var lowTypes = "bbbbbbbbbtstwsbbbbbbbbbbbbbbssstwNN%%%NNNNNN,N,N1111111111NNNNNNNLLLLLLLLLLLLLLLLLLLLLLLLLLNNNNNNLLLLLLLLLLLLLLLLLLLLLLLLLLNNNNbbbbbbsbbbbbbbbbbbbbbbbbbbbbbbbbb,N%%%%NNNNLNNNNN%%11NLNNN1LNNNNNLLLLLLLLLLLLLLLLLLLLLLLNLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLNLLLLLLLL";
            // Character types for codepoints 0x600 to 0x6ff
            var arabicTypes = "rrrrrrrrrrrr,rNNmmmmmmrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrmmmmmmmmmmmmmmrrrrrrrnnnnnnnnnn%nnrrrmrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrmmmmmmmmmmmmmmmmmmmNmmmmrrrrrrrrrrrrrrrrrr";
            function charType(code) {
                if (code <= 0xff) return lowTypes.charAt(code);
                else if (0x590 <= code && code <= 0x5f4) return "R";
                else if (0x600 <= code && code <= 0x6ff) return arabicTypes.charAt(code - 0x600);
                else if (0x700 <= code && code <= 0x8ac) return "r";
                else return "L";
            }

            var bidiRE = /[\u0590-\u05f4\u0600-\u06ff\u0700-\u08ac]/;
            var isNeutral = /[stwN]/, isStrong = /[LRr]/, countsAsLeft = /[Lb1n]/, countsAsNum = /[1n]/;
            // Browsers seem to always treat the boundaries of block elements as being L.
            var outerType = "L";

            return function(str) {
                if (!bidiRE.test(str)) return false;
                var len = str.length, types = [];
                for (var i = 0, type; i < len; ++i)
                    types.push(type = charType(str.charCodeAt(i)));

                // W1. Examine each non-spacing mark (NSM) in the level run, and
                // change the type of the NSM to the type of the previous
                // character. If the NSM is at the start of the level run, it will
                // get the type of sor.
                for (var i = 0, prev = outerType; i < len; ++i) {
                    var type = types[i];
                    if (type == "m") types[i] = prev;
                    else prev = type;
                }

                // W2. Search backwards from each instance of a European number
                // until the first strong type (R, L, AL, or sor) is found. If an
                // AL is found, change the type of the European number to Arabic
                // number.
                // W3. Change all ALs to R.
                for (var i = 0, cur = outerType; i < len; ++i) {
                    var type = types[i];
                    if (type == "1" && cur == "r") types[i] = "n";
                    else if (isStrong.test(type)) { cur = type; if (type == "r") types[i] = "R"; }
                }

                // W4. A single European separator between two European numbers
                // changes to a European number. A single common separator between
                // two numbers of the same type changes to that type.
                for (var i = 1, prev = types[0]; i < len - 1; ++i) {
                    var type = types[i];
                    if (type == "+" && prev == "1" && types[i+1] == "1") types[i] = "1";
                    else if (type == "," && prev == types[i+1] &&
                        (prev == "1" || prev == "n")) types[i] = prev;
                    prev = type;
                }

                // W5. A sequence of European terminators adjacent to European
                // numbers changes to all European numbers.
                // W6. Otherwise, separators and terminators change to Other
                // Neutral.
                for (var i = 0; i < len; ++i) {
                    var type = types[i];
                    if (type == ",") types[i] = "N";
                    else if (type == "%") {
                        for (var end = i + 1; end < len && types[end] == "%"; ++end) {}
                        var replace = (i && types[i-1] == "!") || (end < len - 1 && types[end] == "1") ? "1" : "N";
                        for (var j = i; j < end; ++j) types[j] = replace;
                        i = end - 1;
                    }
                }

                // W7. Search backwards from each instance of a European number
                // until the first strong type (R, L, or sor) is found. If an L is
                // found, then change the type of the European number to L.
                for (var i = 0, cur = outerType; i < len; ++i) {
                    var type = types[i];
                    if (cur == "L" && type == "1") types[i] = "L";
                    else if (isStrong.test(type)) cur = type;
                }

                // N1. A sequence of neutrals takes the direction of the
                // surrounding strong text if the text on both sides has the same
                // direction. European and Arabic numbers act as if they were R in
                // terms of their influence on neutrals. Start-of-level-run (sor)
                // and end-of-level-run (eor) are used at level run boundaries.
                // N2. Any remaining neutrals take the embedding direction.
                for (var i = 0; i < len; ++i) {
                    if (isNeutral.test(types[i])) {
                        for (var end = i + 1; end < len && isNeutral.test(types[end]); ++end) {}
                        var before = (i ? types[i-1] : outerType) == "L";
                        var after = (end < len - 1 ? types[end] : outerType) == "L";
                        var replace = before || after ? "L" : "R";
                        for (var j = i; j < end; ++j) types[j] = replace;
                        i = end - 1;
                    }
                }

                // Here we depart from the documented algorithm, in order to avoid
                // building up an actual levels array. Since there are only three
                // levels (0, 1, 2) in an implementation that doesn't take
                // explicit embedding into account, we can build up the order on
                // the fly, without following the level-based algorithm.
                var order = [], m;
                for (var i = 0; i < len;) {
                    if (countsAsLeft.test(types[i])) {
                        var start = i;
                        for (++i; i < len && countsAsLeft.test(types[i]); ++i) {}
                        order.push({from: start, to: i, level: 0});
                    } else {
                        var pos = i, at = order.length;
                        for (++i; i < len && types[i] != "L"; ++i) {}
                        for (var j = pos; j < i;) {
                            if (countsAsNum.test(types[j])) {
                                if (pos < j) order.splice(at, 0, {from: pos, to: j, level: 1});
                                var nstart = j;
                                for (++j; j < i && countsAsNum.test(types[j]); ++j) {}
                                order.splice(at, 0, {from: nstart, to: j, level: 2});
                                pos = j;
                            } else ++j;
                        }
                        if (pos < i) order.splice(at, 0, {from: pos, to: i, level: 1});
                    }
                }
                if (order[0].level == 1 && (m = str.match(/^\s+/))) {
                    order[0].from = m[0].length;
                    order.unshift({from: 0, to: m[0].length, level: 0});
                }
                if (lst(order).level == 1 && (m = str.match(/\s+$/))) {
                    lst(order).to -= m[0].length;
                    order.push({from: len - m[0].length, to: len, level: 0});
                }
                if (order[0].level != lst(order).level)
                    order.push({from: len, to: len, level: order[0].level});

                return order;
            };
        })();

        // THE END

        CodeMirror.version = "3.15.0";

        return CodeMirror;
    })();

    var listRE = /^(\s*)([*+-]|(\d+)\.)([\w+(\s+\w+)]|[\s*])/,
        emptyListRE = /^(\s*)([*+-]|(\d+)\.)(\s*)$/,
        unorderedBullets = '*+-';

    var inListState = function(cm, pos){
        return cm.getStateAfter(pos.line).list || null;
    };

    var inListOrNot = function(cm){
        var pos = cm.getCursor();
        return inListState(cm, pos);
    };

    CodeMirror.commands.shiftTabAndIndentContinueMarkdownList = function(cm){
        var inList = inListOrNot(cm);

        if(inList !== null){
            cm.execCommand('insertTab');
            return;
        }

        cm.execCommand('indentLess');
    };

    CodeMirror.commands.tabAndIndentContinueMarkdownList = function(cm){
        var inList = inListOrNot(cm);

        if(inList !== null){
            cm.execCommand('insertTab');
            return;
        }

        cm.execCommand('indentMore');
    };

    CodeMirror.commands.newlineAndIndentContinueMarkdownList = function(cm){
        var pos, tok, match, emptyMatch, inList;

        pos = cm.getCursor();
        tok = cm.getTokenAt(pos);
        emptyMatch = cm.getLine(pos.line).match(emptyListRE);
        inList = inListState(cm, pos);

        if (!inList && emptyMatch){
            cm.replaceRange("", {line: pos.line , ch:tok.start}, {line:pos.line , ch:tok.end});
            cm.execCommand('delLineLeft');
            cm.execCommand('newlineAndIndent');
            return;
        }

        if (!inList || !(match = cm.getLine(pos.line).match(listRE))) {
            cm.execCommand('newlineAndIndent');
            return;
        }

        var indent = match[1], after = " ";
        var bullet = unorderedBullets.indexOf(match[2]) >= 0
            ? match[2]
            : (parseInt(match[3], 10) + 1) + '.';

        cm.replaceSelection('\n' + indent + bullet + after, 'end');
    };

    CodeMirror.defineMode("xml", function(config, parserConfig) {
        var indentUnit = config.indentUnit;
        var multilineTagIndentFactor = parserConfig.multilineTagIndentFactor || 1;
        var multilineTagIndentPastTag = parserConfig.multilineTagIndentPastTag || true;

        var Kludges = parserConfig.htmlMode ? {
            autoSelfClosers: {'area': true, 'base': true, 'br': true, 'col': true, 'command': true,
                'embed': true, 'frame': true, 'hr': true, 'img': true, 'input': true,
                'keygen': true, 'link': true, 'meta': true, 'param': true, 'source': true,
                'track': true, 'wbr': true},
            implicitlyClosed: {'dd': true, 'li': true, 'optgroup': true, 'option': true, 'p': true,
                'rp': true, 'rt': true, 'tbody': true, 'td': true, 'tfoot': true,
                'th': true, 'tr': true},
            contextGrabbers: {
                'dd': {'dd': true, 'dt': true},
                'dt': {'dd': true, 'dt': true},
                'li': {'li': true},
                'option': {'option': true, 'optgroup': true},
                'optgroup': {'optgroup': true},
                'p': {'address': true, 'article': true, 'aside': true, 'blockquote': true, 'dir': true,
                    'div': true, 'dl': true, 'fieldset': true, 'footer': true, 'form': true,
                    'h1': true, 'h2': true, 'h3': true, 'h4': true, 'h5': true, 'h6': true,
                    'header': true, 'hgroup': true, 'hr': true, 'menu': true, 'nav': true, 'ol': true,
                    'p': true, 'pre': true, 'section': true, 'table': true, 'ul': true},
                'rp': {'rp': true, 'rt': true},
                'rt': {'rp': true, 'rt': true},
                'tbody': {'tbody': true, 'tfoot': true},
                'td': {'td': true, 'th': true},
                'tfoot': {'tbody': true},
                'th': {'td': true, 'th': true},
                'thead': {'tbody': true, 'tfoot': true},
                'tr': {'tr': true}
            },
            doNotIndent: {"pre": true},
            allowUnquoted: true,
            allowMissing: true
        } : {
            autoSelfClosers: {},
            implicitlyClosed: {},
            contextGrabbers: {},
            doNotIndent: {},
            allowUnquoted: false,
            allowMissing: false
        };
        var alignCDATA = parserConfig.alignCDATA;

        // Return variables for tokenizers
        var tagName, type;

        function inText(stream, state) {
            function chain(parser) {
                state.tokenize = parser;
                return parser(stream, state);
            }

            var ch = stream.next();
            if (ch == "<") {
                if (stream.eat("!")) {
                    if (stream.eat("[")) {
                        if (stream.match("CDATA[")) return chain(inBlock("atom", "]]>"));
                        else return null;
                    } else if (stream.match("--")) {
                        return chain(inBlock("comment", "-->"));
                    } else if (stream.match("DOCTYPE", true, true)) {
                        stream.eatWhile(/[\w\._\-]/);
                        return chain(doctype(1));
                    } else {
                        return null;
                    }
                } else if (stream.eat("?")) {
                    stream.eatWhile(/[\w\._\-]/);
                    state.tokenize = inBlock("meta", "?>");
                    return "meta";
                } else {
                    var isClose = stream.eat("/");
                    tagName = "";
                    var c;
                    while ((c = stream.eat(/[^\s\u00a0=<>\"\'\/?]/))) tagName += c;
                    if (!tagName) return "error";
                    type = isClose ? "closeTag" : "openTag";
                    state.tokenize = inTag;
                    return "tag";
                }
            } else if (ch == "&") {
                var ok;
                if (stream.eat("#")) {
                    if (stream.eat("x")) {
                        ok = stream.eatWhile(/[a-fA-F\d]/) && stream.eat(";");
                    } else {
                        ok = stream.eatWhile(/[\d]/) && stream.eat(";");
                    }
                } else {
                    ok = stream.eatWhile(/[\w\.\-:]/) && stream.eat(";");
                }
                return ok ? "atom" : "error";
            } else {
                stream.eatWhile(/[^&<]/);
                return null;
            }
        }

        function inTag(stream, state) {
            var ch = stream.next();
            if (ch == ">" || (ch == "/" && stream.eat(">"))) {
                state.tokenize = inText;
                type = ch == ">" ? "endTag" : "selfcloseTag";
                return "tag";
            } else if (ch == "=") {
                type = "equals";
                return null;
            } else if (ch == "<") {
                return "error";
            } else if (/[\'\"]/.test(ch)) {
                state.tokenize = inAttribute(ch);
                state.stringStartCol = stream.column();
                return state.tokenize(stream, state);
            } else {
                stream.eatWhile(/[^\s\u00a0=<>\"\']/);
                return "word";
            }
        }

        function inAttribute(quote) {
            var closure = function(stream, state) {
                while (!stream.eol()) {
                    if (stream.next() == quote) {
                        state.tokenize = inTag;
                        break;
                    }
                }
                return "string";
            };
            closure.isInAttribute = true;
            return closure;
        }

        function inBlock(style, terminator) {
            return function(stream, state) {
                while (!stream.eol()) {
                    if (stream.match(terminator)) {
                        state.tokenize = inText;
                        break;
                    }
                    stream.next();
                }
                return style;
            };
        }
        function doctype(depth) {
            return function(stream, state) {
                var ch;
                while ((ch = stream.next()) != null) {
                    if (ch == "<") {
                        state.tokenize = doctype(depth + 1);
                        return state.tokenize(stream, state);
                    } else if (ch == ">") {
                        if (depth == 1) {
                            state.tokenize = inText;
                            break;
                        } else {
                            state.tokenize = doctype(depth - 1);
                            return state.tokenize(stream, state);
                        }
                    }
                }
                return "meta";
            };
        }

        var curState, curStream, setStyle;
        function pass() {
            for (var i = arguments.length - 1; i >= 0; i--) curState.cc.push(arguments[i]);
        }
        function cont() {
            pass.apply(null, arguments);
            return true;
        }

        function pushContext(tagName, startOfLine) {
            var noIndent = Kludges.doNotIndent.hasOwnProperty(tagName) || (curState.context && curState.context.noIndent);
            curState.context = {
                prev: curState.context,
                tagName: tagName,
                indent: curState.indented,
                startOfLine: startOfLine,
                noIndent: noIndent
            };
        }
        function popContext() {
            if (curState.context) curState.context = curState.context.prev;
        }

        function element(type) {
            if (type == "openTag") {
                curState.tagName = tagName;
                curState.tagStart = curStream.column();
                return cont(attributes, endtag(curState.startOfLine));
            } else if (type == "closeTag") {
                var err = false;
                if (curState.context) {
                    if (curState.context.tagName != tagName) {
                        if (Kludges.implicitlyClosed.hasOwnProperty(curState.context.tagName.toLowerCase())) {
                            popContext();
                        }
                        err = !curState.context || curState.context.tagName != tagName;
                    }
                } else {
                    err = true;
                }
                if (err) setStyle = "error";
                return cont(endclosetag(err));
            }
            return cont();
        }
        function endtag(startOfLine) {
            return function(type) {
                var tagName = curState.tagName;
                curState.tagName = curState.tagStart = null;
                if (type == "selfcloseTag" ||
                    (type == "endTag" && Kludges.autoSelfClosers.hasOwnProperty(tagName.toLowerCase()))) {
                    maybePopContext(tagName.toLowerCase());
                    return cont();
                }
                if (type == "endTag") {
                    maybePopContext(tagName.toLowerCase());
                    pushContext(tagName, startOfLine);
                    return cont();
                }
                return cont();
            };
        }
        function endclosetag(err) {
            return function(type) {
                if (err) setStyle = "error";
                if (type == "endTag") { popContext(); return cont(); }
                setStyle = "error";
                return cont(arguments.callee);
            };
        }
        function maybePopContext(nextTagName) {
            var parentTagName;
            while (true) {
                if (!curState.context) {
                    return;
                }
                parentTagName = curState.context.tagName.toLowerCase();
                if (!Kludges.contextGrabbers.hasOwnProperty(parentTagName) ||
                    !Kludges.contextGrabbers[parentTagName].hasOwnProperty(nextTagName)) {
                    return;
                }
                popContext();
            }
        }

        function attributes(type) {
            if (type == "word") {setStyle = "attribute"; return cont(attribute, attributes);}
            if (type == "endTag" || type == "selfcloseTag") return pass();
            setStyle = "error";
            return cont(attributes);
        }
        function attribute(type) {
            if (type == "equals") return cont(attvalue, attributes);
            if (!Kludges.allowMissing) setStyle = "error";
            else if (type == "word") setStyle = "attribute";
            return (type == "endTag" || type == "selfcloseTag") ? pass() : cont();
        }
        function attvalue(type) {
            if (type == "string") return cont(attvaluemaybe);
            if (type == "word" && Kludges.allowUnquoted) {setStyle = "string"; return cont();}
            setStyle = "error";
            return (type == "endTag" || type == "selfCloseTag") ? pass() : cont();
        }
        function attvaluemaybe(type) {
            if (type == "string") return cont(attvaluemaybe);
            else return pass();
        }

        return {
            startState: function() {
                return {tokenize: inText, cc: [], indented: 0, startOfLine: true, tagName: null, tagStart: null, context: null};
            },

            token: function(stream, state) {
                if (!state.tagName && stream.sol()) {
                    state.startOfLine = true;
                    state.indented = stream.indentation();
                }
                if (stream.eatSpace()) return null;

                setStyle = type = tagName = null;
                var style = state.tokenize(stream, state);
                state.type = type;
                if ((style || type) && style != "comment") {
                    curState = state; curStream = stream;
                    while (true) {
                        var comb = state.cc.pop() || element;
                        if (comb(type || style)) break;
                    }
                }
                state.startOfLine = false;
                return setStyle || style;
            },

            indent: function(state, textAfter, fullLine) {
                var context = state.context;
                // Indent multi-line strings (e.g. css).
                if (state.tokenize.isInAttribute) {
                    return state.stringStartCol + 1;
                }
                if ((state.tokenize != inTag && state.tokenize != inText) ||
                    context && context.noIndent)
                    return fullLine ? fullLine.match(/^(\s*)/)[0].length : 0;
                // Indent the starts of attribute names.
                if (state.tagName) {
                    if (multilineTagIndentPastTag)
                        return state.tagStart + state.tagName.length + 2;
                    else
                        return state.tagStart + indentUnit * multilineTagIndentFactor;
                }
                if (alignCDATA && /<!\[CDATA\[/.test(textAfter)) return 0;
                if (context && /^<\//.test(textAfter))
                    context = context.prev;
                while (context && !context.startOfLine)
                    context = context.prev;
                if (context) return context.indent + indentUnit;
                else return 0;
            },

            electricChars: "/",
            blockCommentStart: "<!--",
            blockCommentEnd: "-->",

            configuration: parserConfig.htmlMode ? "html" : "xml",
            helperType: parserConfig.htmlMode ? "html" : "xml"
        };
    });

    CodeMirror.defineMIME("text/xml", "xml");
    CodeMirror.defineMIME("application/xml", "xml");
    if (!CodeMirror.mimeModes.hasOwnProperty("text/html"))
        CodeMirror.defineMIME("text/html", {name: "xml", htmlMode: true});

    CodeMirror.defineMode("markdown", function(cmCfg, modeCfg) {

        var htmlFound = CodeMirror.modes.hasOwnProperty("xml");
        var htmlMode = CodeMirror.getMode(cmCfg, htmlFound ? {name: "xml", htmlMode: true} : "text/plain");
        var aliases = {
            html: "htmlmixed",
            js: "javascript",
            json: "application/json",
            c: "text/x-csrc",
            "c++": "text/x-c++src",
            java: "text/x-java",
            csharp: "text/x-csharp",
            "c#": "text/x-csharp",
            scala: "text/x-scala"
        };

        var getMode = (function () {
            var i, modes = {}, mimes = {}, mime;

            var list = [];
            for (var m in CodeMirror.modes)
                if (CodeMirror.modes.propertyIsEnumerable(m)) list.push(m);
            for (i = 0; i < list.length; i++) {
                modes[list[i]] = list[i];
            }
            var mimesList = [];
            for (var m in CodeMirror.mimeModes)
                if (CodeMirror.mimeModes.propertyIsEnumerable(m))
                    mimesList.push({mime: m, mode: CodeMirror.mimeModes[m]});
            for (i = 0; i < mimesList.length; i++) {
                mime = mimesList[i].mime;
                mimes[mime] = mimesList[i].mime;
            }

            for (var a in aliases) {
                if (aliases[a] in modes || aliases[a] in mimes)
                    modes[a] = aliases[a];
            }

            return function (lang) {
                return modes[lang] ? CodeMirror.getMode(cmCfg, modes[lang]) : null;
            };
        }());

        // Should underscores in words open/close em/strong?
        if (modeCfg.underscoresBreakWords === undefined)
            modeCfg.underscoresBreakWords = true;

        // Turn on fenced code blocks? ("```" to start/end)
        if (modeCfg.fencedCodeBlocks === undefined) modeCfg.fencedCodeBlocks = false;

        // Turn on task lists? ("- [ ] " and "- [x] ")
        if (modeCfg.taskLists === undefined) modeCfg.taskLists = false;

        var codeDepth = 0;

        var header   = 'header'
            ,   code     = 'comment'
            ,   quote1   = 'atom'
            ,   quote2   = 'number'
            ,   list1    = 'variable-2'
            ,   list2    = 'variable-3'
            ,   list3    = 'keyword'
            ,   hr       = 'hr'
            ,   image    = 'tag'
            ,   linkinline = 'link'
            ,   linkemail = 'link'
            ,   linktext = 'link'
            ,   linkhref = 'string'
            ,   em       = 'em'
            ,   strong   = 'strong'
            ,   strike   = 'strike';

        var hrRE = /^([*\-=_])(?:\s*\1){4,}\s*$/
            ,   ulRE = /^[*\-+]\s+/
            ,   olRE = /^[0-9]+\.\s+/
            ,   taskListRE = /^\[(x| )\](?=\s)/ // Must follow ulRE or olRE
            ,   headerRE = /^(?:\={1,}|-{1,})$/
            ,   textRE = /^[^!\[\]*_~\\<>` "'(]+/;

        function switchInline(stream, state, f) {
            state.f = state.inline = f;
            return f(stream, state);
        }

        function switchBlock(stream, state, f) {
            state.f = state.block = f;
            return f(stream, state);
        }


        // Blocks

        function blankLine(state) {
            // Reset linkTitle state
            state.linkTitle = false;
            // Reset EM state
            state.em = false;
            // Reset STRONG state
            state.strong = false;
            // Reset STRIKE state
            state.strike = false;

            // Reset state.quote
            state.quote = 0;
            if (!htmlFound && state.f == htmlBlock) {
                state.f = inlineNormal;
                state.block = blockNormal;
            }
            // Reset state.trailingSpace
            state.trailingSpace = 0;
            state.trailingSpaceNewLine = false;
            // Mark this line as blank
            state.thisLineHasContent = false;
            return null;
        }

        function blockNormal(stream, state) {

            var prevLineIsList = (state.list !== false);
            if (state.list !== false && state.indentationDiff >= 0) { // Continued list
                if (state.indentationDiff < 4) { // Only adjust indentation if *not* a code block
                    state.indentation -= state.indentationDiff;
                }
                state.list = null;
            } else if (state.list !== false && state.indentation > 0) {
                state.list = null;
                state.listDepth = Math.floor(state.indentation / 4);
            } else if (state.list !== false) { // No longer a list
                state.list = false;
                state.listDepth = 0;
            }

            if (state.indentationDiff >= 4) {
                state.indentation -= 4;
                stream.skipToEnd();
                return code;
            } else if (stream.eatSpace()) {
                return null;
            } else if (stream.peek() === '#' || (state.prevLineHasContent && stream.match(headerRE)) ) {
                state.header = true;
            } else if (stream.eat('>')) {
                state.indentation++;
                state.quote = 1;
                stream.eatSpace();
                while (stream.eat('>')) {
                    stream.eatSpace();
                    state.quote++;
                }
            } else if (stream.peek() === '[') {
                return switchInline(stream, state, footnoteLink);
            } else if (stream.match(hrRE, true)) {
                return hr;
            } else if ((!state.prevLineHasContent || prevLineIsList) && (stream.match(ulRE, true) || stream.match(olRE, true))) {
                state.indentation += 4;
                state.list = true;
                state.listDepth++;
                if (modeCfg.taskLists && stream.match(taskListRE, false)) {
                    state.taskList = true;
                }
            } else if (modeCfg.fencedCodeBlocks && stream.match(/^```([\w+#]*)/, true)) {
                // try switching mode
                state.localMode = getMode(RegExp.$1);
                if (state.localMode) state.localState = state.localMode.startState();
                switchBlock(stream, state, local);
                return code;
            }

            return switchInline(stream, state, state.inline);
        }

        function htmlBlock(stream, state) {
            var style = htmlMode.token(stream, state.htmlState);
            if (htmlFound && style === 'tag' && state.htmlState.type !== 'openTag' && !state.htmlState.context) {
                state.f = inlineNormal;
                state.block = blockNormal;
            }
            if (state.md_inside && stream.current().indexOf(">")!=-1) {
                state.f = inlineNormal;
                state.block = blockNormal;
                state.htmlState.context = undefined;
            }
            return style;
        }

        function local(stream, state) {
            if (stream.sol() && stream.match(/^```/, true)) {
                state.localMode = state.localState = null;
                state.f = inlineNormal;
                state.block = blockNormal;
                return code;
            } else if (state.localMode) {
                return state.localMode.token(stream, state.localState);
            } else {
                stream.skipToEnd();
                return code;
            }
        }

        // Inline
        function getType(state) {
            var styles = [];

            if (state.taskOpen) { return "meta"; }
            if (state.taskClosed) { return "property"; }

            if (state.strong) { styles.push(strong); }
            if (state.strike) { styles.push(strike); }
            if (state.em) { styles.push(em); }

            if (state.linkText) { styles.push(linktext); }

            if (state.code) { styles.push(code); }

            if (state.header) { styles.push(header); }
            if (state.quote) { styles.push(state.quote % 2 ? quote1 : quote2); }
            if (state.list !== false) {
                var listMod = (state.listDepth - 1) % 3;
                if (!listMod) {
                    styles.push(list1);
                } else if (listMod === 1) {
                    styles.push(list2);
                } else {
                    styles.push(list3);
                }
            }

            if (state.trailingSpaceNewLine) {
                styles.push("trailing-space-new-line");
            } else if (state.trailingSpace) {
                styles.push("trailing-space-" + (state.trailingSpace % 2 ? "a" : "b"));
            }

            return styles.length ? styles.join(' ') : null;
        }

        function handleText(stream, state) {
            if (stream.match(textRE, true)) {
                return getType(state);
            }
            return undefined;
        }

        function inlineNormal(stream, state) {
            var style = state.text(stream, state);
            if (typeof style !== 'undefined')
                return style;

            if (state.list) { // List marker (*, +, -, 1., etc)
                state.list = null;
                return getType(state);
            }

            if (state.taskList) {
                var taskOpen = stream.match(taskListRE, true)[1] !== "x";
                if (taskOpen) state.taskOpen = true;
                else state.taskClosed = true;
                state.taskList = false;
                return getType(state);
            }

            state.taskOpen = false;
            state.taskClosed = false;

            var ch = stream.next();

            if (ch === '\\') {
                stream.next();
                return getType(state);
            }

            // Matches link titles present on next line
            if (state.linkTitle) {
                state.linkTitle = false;
                var matchCh = ch;
                if (ch === '(') {
                    matchCh = ')';
                }
                matchCh = (matchCh+'').replace(/([.?*+^$[\]\\(){}|-])/g, "\\$1");
                var regex = '^\\s*(?:[^' + matchCh + '\\\\]+|\\\\\\\\|\\\\.)' + matchCh;
                if (stream.match(new RegExp(regex), true)) {
                    return linkhref;
                }
            }

            // If this block is changed, it may need to be updated in GFM mode
            if (ch === '`') {
                var t = getType(state);
                var before = stream.pos;
                stream.eatWhile('`');
                var difference = 1 + stream.pos - before;
                if (!state.code) {
                    codeDepth = difference;
                    state.code = true;
                    return getType(state);
                } else {
                    if (difference === codeDepth) { // Must be exact
                        state.code = false;
                        return t;
                    }
                    return getType(state);
                }
            } else if (state.code) {
                return getType(state);
            }

            if (ch === '!' && stream.match(/\[[^\]]*\] ?(?:\(|\[)/, false)) {
                stream.match(/\[[^\]]*\]/);
                state.inline = state.f = linkHref;
                return image;
            }

            if (ch === '[' && stream.match(/.*\](\(| ?\[)/, false)) {
                state.linkText = true;
                return getType(state);
            }

            if (ch === ']' && state.linkText) {
                var type = getType(state);
                state.linkText = false;
                state.inline = state.f = linkHref;
                return type;
            }

            if (ch === '<' && stream.match(/^(https?|ftps?):\/\/(?:[^\\>]|\\.)+>/, false)) {
                return switchInline(stream, state, inlineElement(linkinline, '>'));
            }

            if (ch === '<' && stream.match(/^[^> \\]+@(?:[^\\>]|\\.)+>/, false)) {
                return switchInline(stream, state, inlineElement(linkemail, '>'));
            }

            if (ch === '<' && stream.match(/^\w/, false)) {
                if (stream.string.indexOf(">")!=-1) {
                    var atts = stream.string.substring(1,stream.string.indexOf(">"));
                    if (/markdown\s*=\s*('|"){0,1}1('|"){0,1}/.test(atts)) {
                        state.md_inside = true;
                    }
                }
                stream.backUp(1);
                return switchBlock(stream, state, htmlBlock);
            }

            if (ch === '<' && stream.match(/^\/\w*?>/)) {
                state.md_inside = false;
                return "tag";
            }

            var ignoreUnderscore = false;
            if (!modeCfg.underscoresBreakWords) {
                if (ch === '_' && stream.peek() !== '_' && stream.match(/(\w)/, false)) {
                    var prevPos = stream.pos - 2;
                    if (prevPos >= 0) {
                        var prevCh = stream.string.charAt(prevPos);
                        if (prevCh !== '_' && prevCh.match(/(\w)/, false)) {
                            ignoreUnderscore = true;
                        }
                    }
                }
            }
            var t = getType(state);
            if (ch === '*' || (ch === '_' && !ignoreUnderscore)) {
                if (state.strong === ch && stream.eat(ch) && stream.peek(ch)) { // Remove STRONG
                    state.strong = false;
                    return t;
                } else if (!state.strong && stream.eat(ch) && stream.peek(ch)) { // Add STRONG
                    state.strong = ch;
                    return getType(state);
                } else if (state.em === ch) { // Remove EM
                    state.em = false;
                    return t;
                } else if (!state.em) { // Add EM
                    state.em = ch;
                    return getType(state);
                }
            } else if (ch === '~'){
                if (state.strike === ch && stream.eat(ch)) { // Remove SRTIKE
                    state.strike = false;
                    return t;
                } else if (!state.strike && stream.eat(ch)) { // Add STRIKE
                    state.strike = ch;
                    return getType(state);
                }
            } else if (ch === ' ') {
                if (stream.eat('*') || stream.eat('_')) { // Probably surrounded by spaces
                    if (stream.peek() === ' ') { // Surrounded by spaces, ignore
                        return getType(state);
                    } else { // Not surrounded by spaces, back up pointer
                        stream.backUp(1);
                    }
                }
            }

            if (ch === ' ') {
                if (stream.match(/ +$/, false)) {
                    state.trailingSpace++;
                } else if (state.trailingSpace) {
                    state.trailingSpaceNewLine = true;
                }
            }

            return getType(state);
        }

        function linkHref(stream, state) {
            // Check if space, and return NULL if so (to avoid marking the space)
            if(stream.eatSpace()){
                return null;
            }
            var ch = stream.next();
            if (ch === '(' || ch === '[') {
                return switchInline(stream, state, inlineElement(linkhref, ch === '(' ? ')' : ']'));
            }
            return 'error';
        }

        function footnoteLink(stream, state) {
            if (stream.match(/^[^\]]*\]:/, true)) {
                state.f = footnoteUrl;
                return linktext;
            }
            return switchInline(stream, state, inlineNormal);
        }

        function footnoteUrl(stream, state) {
            // Check if space, and return NULL if so (to avoid marking the space)
            if(stream.eatSpace()){
                return null;
            }
            // Match URL
            stream.match(/^[^\s]+/, true);
            // Check for link title
            if (stream.peek() === undefined) { // End of line, set flag to check next line
                state.linkTitle = true;
            } else { // More content on line, check if link title
                stream.match(/^(?:\s+(?:"(?:[^"\\]|\\\\|\\.)+"|'(?:[^'\\]|\\\\|\\.)+'|\((?:[^)\\]|\\\\|\\.)+\)))?/, true);
            }
            state.f = state.inline = inlineNormal;
            return linkhref;
        }

        var savedInlineRE = [];
        function inlineRE(endChar) {
            if (!savedInlineRE[endChar]) {
                // Escape endChar for RegExp (taken from http://stackoverflow.com/a/494122/526741)
                endChar = (endChar+'').replace(/([.?*+^$[\]\\(){}|-])/g, "\\$1");
                // Match any non-endChar, escaped character, as well as the closing
                // endChar.
                savedInlineRE[endChar] = new RegExp('^(?:[^\\\\]|\\\\.)*?(' + endChar + ')');
            }
            return savedInlineRE[endChar];
        }

        function inlineElement(type, endChar, next) {
            next = next || inlineNormal;
            return function(stream, state) {
                stream.match(inlineRE(endChar));
                state.inline = state.f = next;
                return type;
            };
        }

        return {
            startState: function() {
                return {
                    f: blockNormal,

                    prevLineHasContent: false,
                    thisLineHasContent: false,

                    block: blockNormal,
                    htmlState: CodeMirror.startState(htmlMode),
                    indentation: 0,

                    inline: inlineNormal,
                    text: handleText,

                    linkText: false,
                    linkTitle: false,
                    em: false,
                    strong: false,
                    strike: false,
                    header: false,
                    taskList: false,
                    list: false,
                    listDepth: 0,
                    quote: 0,
                    trailingSpace: 0,
                    trailingSpaceNewLine: false
                };
            },

            copyState: function(s) {
                return {
                    f: s.f,

                    prevLineHasContent: s.prevLineHasContent,
                    thisLineHasContent: s.thisLineHasContent,

                    block: s.block,
                    htmlState: CodeMirror.copyState(htmlMode, s.htmlState),
                    indentation: s.indentation,

                    localMode: s.localMode,
                    localState: s.localMode ? CodeMirror.copyState(s.localMode, s.localState) : null,

                    inline: s.inline,
                    text: s.text,
                    linkTitle: s.linkTitle,
                    em: s.em,
                    strong: s.strong,
                    strike: s.strike,
                    header: s.header,
                    taskList: s.taskList,
                    list: s.list,
                    listDepth: s.listDepth,
                    quote: s.quote,
                    trailingSpace: s.trailingSpace,
                    trailingSpaceNewLine: s.trailingSpaceNewLine,
                    md_inside: s.md_inside
                };
            },

            token: function(stream, state) {
                if (stream.sol()) {
                    if (stream.match(/^\s*$/, true)) {
                        state.prevLineHasContent = false;
                        return blankLine(state);
                    } else {
                        state.prevLineHasContent = state.thisLineHasContent;
                        state.thisLineHasContent = true;
                    }

                    // Reset state.header
                    state.header = false;

                    // Reset state.taskList
                    state.taskList = false;

                    // Reset state.code
                    state.code = false;

                    // Reset state.trailingSpace
                    state.trailingSpace = 0;
                    state.trailingSpaceNewLine = false;

                    state.f = state.block;
                    var indentation = stream.match(/^\s*/, true)[0].replace(/\t/g, '    ').length;
                    var difference = Math.floor((indentation - state.indentation) / 4) * 4;
                    if (difference > 4) difference = 4;
                    var adjustedIndentation = state.indentation + difference;
                    state.indentationDiff = adjustedIndentation - state.indentation;
                    state.indentation = adjustedIndentation;
                    if (indentation > 0) return null;
                }
                return state.f(stream, state);
            },

            blankLine: blankLine,

            getType: getType
        };

    }, "xml");

    CodeMirror.defineMIME("text/x-markdown", "markdown");


    var isMac = /Mac/.test(navigator.platform);

    var shortcuts = {
        'Cmd-Alt-1': toggleHeadline,
        'Cmd-Alt-2': toggleHeading,
        'Cmd-B': toggleBold,
        'Cmd-I': toggleItalic,
        'Cmd-K': drawLink,
        'Cmd-Alt-I': drawImage,
        "Cmd-'": toggleBlockquote,
        "Cmd-,": drawCode,
        'Cmd-Alt-L': toggleOrderedList,
        'Cmd-L': toggleUnOrderedList,
        'Cmd-Z': undo,
        'Cmd-Shift-Z': redo
    };


    /**
     * Fix shortcut. Mac use Command, others use Ctrl.
     */
    function fixShortcut(name) {
        if (isMac) {
            name = name.replace('Ctrl', 'Cmd');
        } else {
            name = name.replace('Cmd', 'Ctrl');
        }
        return name;
    }


    /**
     * Create icon element for toolbar.
     */
    function createIcon(name, options) {
        options = options || {};
        var el = document.createElement('a');

        var shortcut = options.shortcut || shortcuts[name];
        if (shortcut) {
            shortcut = fixShortcut(shortcut);
            el.title = shortcut;
            el.title = el.title.replace('Cmd', '⌘');
            if (isMac) {
                el.title = el.title.replace('Alt', '⌥');
            }
        }

        el.className = options.className || 'icon-' + name;
        return el;
    }

    function createSep() {
        var el = document.createElement('i');
        el.className = 'separator';
        el.innerHTML = '|';
        return el;
    }


    /**
     * The state of CodeMirror at the given position.
     */
    function getState(cm, pos) {
        pos = pos || cm.getCursor('start');
        var stat = cm.getTokenAt(pos);
        if (!stat.type) return {};

        var types = stat.type.split(' ');

        var ret = {}, data, text;
        for (var i = 0; i < types.length; i++) {
            data = types[i];
            if (data === 'strong') {
                ret.bold = true;
            } else if (data === 'variable-2') {
                text = cm.getLine(pos.line);
                if (/^\s*\d+\.\s/.test(text)) {
                    ret['list-ol'] = true;
                } else {
                    ret['list-ul'] = true;
                }
            } else if (data === 'atom') {
                ret.quote = true;
            } else if (data === 'em') {
                ret.italic = true;
            } else if (data === 'header') {
                text = cm.getLine(pos.line);
                if (/^\s*\##\s/.test(text)) {
                    ret['heading'] = true;
                }else {
                    ret['headline'] = true;
                }
            }
        }
        return ret;
    }


    /**
     * Toggle full screen of the editor.
     */
    function toggleFullScreen(editor) {
        var el = editor.codemirror.getWrapperElement();

        // https://developer.mozilla.org/en-US/docs/DOM/Using_fullscreen_mode
        var doc = document;
        var isFull = doc.fullScreen || doc.mozFullScreen || doc.webkitFullScreen;
        var request = function() {
            if (el.requestFullScreen) {
                el.requestFullScreen();
            } else if (el.mozRequestFullScreen) {
                el.mozRequestFullScreen();
            } else if (el.webkitRequestFullScreen) {
                el.webkitRequestFullScreen(Element.ALLOW_KEYBOARD_INPUT);
            }
        };
        var cancel = function() {
            if (doc.cancelFullScreen) {
                doc.cancelFullScreen();
            } else if (doc.mozCancelFullScreen) {
                doc.mozCancelFullScreen();
            } else if (doc.webkitCancelFullScreen) {
                doc.webkitCancelFullScreen();
            }
        };
        if (!isFull) {
            request();
        } else if (cancel) {
            cancel();
        }
    }

    /**
     * Action for toggling heading.
     */
    function toggleHeadline(editor) {
        var cm = editor.codemirror;
        _toggleLine(cm, 'headline');
    }

    function toggleHeading(editor) {
        var cm = editor.codemirror;
        _toggleLine(cm, 'heading');
    }


    /**
     * Action for toggling bold.
     */
    function toggleBold(editor) {
        var cm = editor.codemirror;
        var stat = getState(cm);

        var text;
        var start = '**';
        var end = '**';

        var startPoint = cm.getCursor('start');
        var endPoint = cm.getCursor('end');
        if (stat.bold) {
            text = cm.getLine(startPoint.line);
            start = text.slice(0, startPoint.ch);
            end = text.slice(startPoint.ch);

            start = start.replace(/^(.*)?(\*|\_){2}(\S+.*)?$/, '$1$3');
            end = end.replace(/^(.*\S+)?(\*|\_){2}(\s+.*)?$/, '$1$3');
            startPoint.ch -= 2;
            endPoint.ch -= 2;
            cm.setLine(startPoint.line, start + end);
        } else {
            text = cm.getSelection();
            cm.replaceSelection(start + text + end);

            startPoint.ch += 2;
            endPoint.ch += 2;
        }
        cm.setSelection(startPoint, endPoint);
        cm.focus();
    }


    /**
     * Action for toggling italic.
     */
    function toggleItalic(editor) {
        var cm = editor.codemirror;
        var stat = getState(cm);

        var text;
        var start = '_';
        var end = '_';

        var startPoint = cm.getCursor('start');
        var endPoint = cm.getCursor('end');
        if (stat.italic) {
            text = cm.getLine(startPoint.line);
            start = text.slice(0, startPoint.ch);
            end = text.slice(startPoint.ch);

            start = start.replace(/^(._)?(\*|\_)(\S+._)?$/, '$1$3');
            end = end.replace(/^(._\S+)?(\*|\_)(\s+._)?$/, '$1$3');
            startPoint.ch -= 1;
            endPoint.ch -= 1;
            cm.setLine(startPoint.line, start + end);
        } else {
            text = cm.getSelection();
            cm.replaceSelection(start + text + end);

            startPoint.ch += 1;
            endPoint.ch += 1;
        }
        cm.setSelection(startPoint, endPoint);
        cm.focus();
    }


    /**
     * Action for toggling blockquote.
     */
    function toggleBlockquote(editor) {
        var cm = editor.codemirror;
        _toggleLine(cm, 'quote');
    }

    function drawCode(editor) {
        var cm = editor.codemirror;
        var stat = getState(cm);
        _replaceSelection(cm, stat.code, '\n\n```\n ', '在这里书写代码片  \n```\n\n');
    }


    /**
     * Action for toggling ul.
     */
    function toggleUnOrderedList(editor) {
        var cm = editor.codemirror;
        _toggleLine(cm, 'list-ul');
    }


    /**
     * Action for toggling ol.
     */
    function toggleOrderedList(editor) {
        var cm = editor.codemirror;
        _toggleLine(cm, 'list-ol');
    }


    /**
     * Action for drawing a link.
     */
    function drawLink(editor) {
        $('.cm_dialog').fadeIn(300);
        $('.cm_add_link').slideDown(300);
        $('.cm_add_img').slideUp(300);
    }
    function cmDrawLink(editor, prefix_str) {
        var cm = editor.codemirror;
        var stat = getState(cm);
        var cm_link_txt = $('#'+prefix_str+'cm_link_txt').val();
        var cm_link_url = $('#'+prefix_str+'cm_link_url').val();
        var cm_link_tit = $('#'+prefix_str+'cm_link_tit').val();
        if(cm_link_txt!="" || cm_link_url!="" || cm_link_tit!=""){
           _replaceSelection(cm, stat.link, '[',cm_link_txt +']('+cm_link_url+' "'+cm_link_tit+'")');
        }
        $('.cm_add_link').slideUp(300);
        $('.cm_dialog').fadeOut(300);
    }


    /**
     * Action for drawing an img.
     */
    function drawImage(editor) {
        $('.cm_dialog').fadeIn(300);
        $('.cm_add_link').slideUp(300);
        $('.cm_add_img').slideDown(300);
    }
    function cmDrawImage(editor, prefix_str) {
        var cm = editor.codemirror;
        var stat = getState(cm);
        var cm_img_url = $('#'+prefix_str+'cm_img_url').val();
        var cm_img_alt = $('#'+prefix_str+'cm_img_alt').val();
        if(cm_img_url!="" || cm_img_alt!=""){
            _replaceSelection(cm, stat.image, '![', cm_img_alt+']('+cm_img_url+')');
        }
        $('.cm_add_img').slideUp(300);
        $('.cm_dialog').fadeOut(300);
    }

    function cmDrawImageUp(editor, url) {
        var cm = editor.codemirror;
        var stat = getState(cm);
        _replaceSelection(cm, stat.image, '![', '图片说明]('+ url +')');
        $('.cm_add_img').slideUp(300);
        $('.cm_dialog').fadeOut(300);
    }

    window.cmDrawLink = cmDrawLink;
    window.cmDrawImage = cmDrawImage;
    window.cmDrawImageUp = cmDrawImageUp;

    /**
     * Undo action.
     */
    function undo(editor) {
        var cm = editor.codemirror;
        cm.undo();
        cm.focus();
    }


    /**
     * Redo action.
     */
    function redo(editor) {
        var cm = editor.codemirror;
        cm.redo();
        cm.focus();
    }

    /**
     * Preview action.
     */
    function togglePreview(editor) {
        var toolbar = editor.toolbar.preview;
        var parse = editor.constructor.markdown;
        var cm = editor.codemirror;
        var wrapper = cm.getWrapperElement();
        var preview = wrapper.lastChild;
        if (!/editor-preview/.test(preview.className)) {
            preview = document.createElement('div');
            preview.className = 'editor-preview';
            wrapper.appendChild(preview);
        }
        if (/editor-preview-active/.test(preview.className)) {
            preview.className = preview.className.replace(
                /\s*editor-preview-active\s*/g, ''
            );
            toolbar.className = toolbar.className.replace(/\s*active\s*/g, '');
        } else {
            /* When the preview button is clicked for the first time,
             * give some time for the transition from editor.css to fire and the view to slide from right to left,
             * instead of just appearing.
             */
            setTimeout(function() {preview.className += ' editor-preview-active'}, 1);
            toolbar.className += ' active';
        }
        var text = cm.getValue();
        preview.innerHTML = parse(text);
    }

    function _replaceSelection(cm, active, start, end) {
        var text;
        var startPoint = cm.getCursor('start');
        var endPoint = cm.getCursor('end');
        if (active) {
            text = cm.getLine(startPoint.line);
            start = text.slice(0, startPoint.ch);
            end = text.slice(startPoint.ch);
            cm.setLine(startPoint.line, start + end);
        } else {
            text = cm.getSelection();
            cm.replaceSelection(start + text + end);

            startPoint.ch += start.length;
            endPoint.ch += start.length;
        }
        cm.setSelection(startPoint, endPoint);
        cm.focus();
    }


    function _toggleLine(cm, name) {
        var stat = getState(cm);
        var startPoint = cm.getCursor('start');
        var endPoint = cm.getCursor('end');
        var repl = {
            headline: /^(\s*)\#\s+/,
            heading: /^(\s*)\##\s+/,
            quote: /^(\s*)\>\s+/,
            'list-ul': /^(\s*)(\*|\-|\+)\s+/,
            'list-ol': /^(\s*)\d+\.\s+/
        };
        var map = {
            headline: '# ',
            heading: '## ',
            quote: '> ',
            'list-ul': '* ',
            'list-ol': '1. '
        };
        for (var i = startPoint.line; i <= endPoint.line; i++) {
            (function(i) {
                var text = cm.getLine(i);
                if (stat[name]) {
                    text = text.replace(repl[name], '$1');
                } else {
                    text = map[name] + text;
                }
                cm.setLine(i, text);
            })(i);
        }
        cm.focus();
    }


    /* The right word count in respect for CJK. */
    function wordCount(data) {
        var pattern = /[a-zA-Z0-9_\u0392-\u03c9]+|[\u4E00-\u9FFF\u3400-\u4dbf\uf900-\ufaff\u3040-\u309f\uac00-\ud7af]+/g;
        var m = data.match(pattern);
        var count = 0;
        if( m === null ) return count;
        for (var i = 0; i < m.length; i++) {
            if (m[i].charCodeAt(0) >= 0x4E00) {
                count += m[i].length;
            } else {
                count += 1;
            }
        }
        return count;
    }

    var toolbar = [
        '|',
        {name: 'headline', action: toggleHeadline,title:'标题一（Ctrl+Alt+1）'},
        {name: 'heading', action: toggleHeading,title:'标题二（Ctrl+Alt+2）'},
        {name: 'bold', action: toggleBold,title:'粗体（Ctrl+B）'},
        {name: 'italic', action: toggleItalic,title:'斜体（Ctrl+I）'},
        '|',

        {name: 'quote-left', action: toggleBlockquote,title:'引用（Ctrl+’）'},
        {name: 'code', action: drawCode,title:'插入代码片（Ctrl+,）'},
        {name: 'list-ul', action: toggleUnOrderedList,title:'无序列表（Ctrl+L）'},
        {name: 'list-ol', action: toggleOrderedList,title:'有序列表（Ctrl+Alt+L）'},
        '|',

        {name: 'link', title:'添加链接（Ctrl+K）'},    //action: drawLink,
        {name: 'picture', title:'添加图片（Ctrl+Alt+I）'},   //action: drawImage,
        '|',

        {name: 'reply', action: undo,title:'撤退（Ctrl+Z）'},
        {name: 'share-alt', action: redo,title:'前进（Ctrl+Shift+Z）'},
        '|',
        {name: 'info', action: 'http://ask.csdn.net/pages/markdown',title:'markdown语法参考'},
        {name: 'preview', action: togglePreview,title:'预览'},
        //{name: 'fullscreen', action: toggleFullScreen},
        '|'
    ];

    /**
     * Interface of Editor.
     */
    function Editor(options) {
        options = options || {};

        if (options.element) {
            this.element = options.element;
        }

        options.toolbar = options.toolbar || Editor.toolbar;
        // you can customize toolbar with object
        // [{name: 'bold', shortcut: 'Ctrl-B', className: 'icon-bold'}]

        if (!options.hasOwnProperty('status')) {
            options.status = ['lines', 'words', 'cursor'];
        }

        this.options = options;

        // If user has passed an element, it should auto rendered
        if (this.element) {
            this.render();
        }
    }

    /**
     * Default toolbar elements.
     */
    Editor.toolbar = toolbar;

    /**
     * Default markdown render.
     */
    Editor.markdown = function(text) {
        if (window.marked) {
            // use marked as markdown parser
            return marked(text);
        }
    };

    /**
     * Render editor to the given element.
     */
    Editor.prototype.render = function(el) {
        if (!el) {
            el = this.element || document.getElementsByTagName('textarea')[0];
        }

        if (this._rendered && this._rendered === el) {
            // Already rendered.
            return;
        }

        this.element = el;
        var options = this.options;

        var self = this;
        var keyMaps = {};

        for (var key in shortcuts) {
            (function(key) {
                keyMaps[fixShortcut(key)] = function(cm) {
                    shortcuts[key](self);
                };
            })(key);
        }

        keyMaps["Enter"] = "newlineAndIndentContinueMarkdownList";
        keyMaps['Tab'] = 'tabAndIndentContinueMarkdownList';
        keyMaps['Shift-Tab'] = 'shiftTabAndIndentContinueMarkdownList';

        this.codemirror = CodeMirror.fromTextArea(el, {
            mode: 'markdown',
            theme: 'paper',
            tabSize: '2',
            indentWithTabs: true,
            lineNumbers: false,
            autofocus: true,
            extraKeys: keyMaps
        });

        if (options.toolbar !== false) {
            this.createToolbar();
        }
        if (options.status !== false) {
            this.createStatusbar();
        }

        this._rendered = this.element;
    };

    Editor.prototype.createToolbar = function(items) {
        items = items || this.options.toolbar;

        if (!items || items.length === 0) {
            return;
        }

        var bar = document.createElement('div');
        bar.className = 'editor-toolbar';

        var self = this;

        var el;
        self.toolbar = {};

        for (var i = 0; i < items.length; i++) {
            (function(item) {
                var el;
                if (item.name) {
                    el = createIcon(item.name, item);
                } else if (item === '|') {
                    el = createSep();
                } else {
                    el = createIcon(item);
                }

                // bind events, special for info
                if (item.action) {
                    if (typeof item.action === 'function') {
                        el.onclick = function(e) {
                            item.action(self);
                        };
                    } else if (typeof item.action === 'string') {
                        el.href = item.action;
                        el.target = '_blank';
                    }
                }
                if(item.title){
                    el.title = item.title;
                }
                self.toolbar[item.name || item] = el;
                bar.appendChild(el);
            })(items[i]);
        }

        var cm = this.codemirror;
        cm.on('cursorActivity', function() {
            var stat = getState(cm);

            for (var key in self.toolbar) {
                (function(key) {
                    var el = self.toolbar[key];
                    if (stat[key]) {
                        el.className += ' active';
                    } else {
                        el.className = el.className.replace(/\s*active\s*/g, '');
                    }
                })(key);
            }
        });

        var cmWrapper = cm.getWrapperElement();
        cmWrapper.parentNode.insertBefore(bar, cmWrapper);
        return bar;
    };

    Editor.prototype.createStatusbar = function(status) {
        status = status || this.options.status;

        if (!status || status.length === 0) return;

        var bar = document.createElement('div');
        bar.className = 'editor-statusbar';

        var pos, cm = this.codemirror;
        for (var i = 0; i < status.length; i++) {
            (function(name) {
                var el = document.createElement('span');
                el.className = name;
                if (name === 'words') {
                    el.innerHTML = '0';
                    cm.on('update', function() {
                        el.innerHTML = wordCount(cm.getValue());
                    });
                } else if (name === 'lines') {
                    el.innerHTML = '0';
                    cm.on('update', function() {
                        el.innerHTML = cm.lineCount();
                    });
                } else if (name === 'cursor') {
                    el.innerHTML = '0:0';
                    cm.on('cursorActivity', function() {
                        pos = cm.getCursor();
                        el.innerHTML = pos.line + ':' + pos.ch;
                    });
                }
                bar.appendChild(el);
            })(status[i]);
        }
        var cmWrapper = this.codemirror.getWrapperElement();
        cmWrapper.parentNode.insertBefore(bar, cmWrapper.nextSibling);
        return bar;
    };

    /**
     * Get or set the text content.
     */
    Editor.prototype.value = function(val) {
        if (val) {
            this.codemirror.getDoc().setValue(val);
            return this;
        } else {
            return this.codemirror.getValue();
        }
    };


    /**
     * Bind static methods for exports.
     */
    Editor.toggleHeadline = toggleHeadline;
    Editor.toggleHeading = toggleHeading;
    Editor.toggleBold = toggleBold;
    Editor.toggleItalic = toggleItalic;
    Editor.toggleBlockquote = toggleBlockquote;
    Editor.drawCode = drawCode;
    Editor.toggleUnOrderedList = toggleUnOrderedList;
    Editor.toggleOrderedList = toggleOrderedList;
    Editor.drawLink = drawLink;
    Editor.drawImage = drawImage;
    Editor.undo = undo;
    Editor.redo = redo;
    Editor.togglePreview = togglePreview;
    Editor.toggleFullScreen = toggleFullScreen;

    /**
     * Bind instance methods for exports.
     */
    Editor.prototype.toggleHeadline = function() {
        toggleHeadline(this);
    };
    Editor.prototype.toggleHeading = function() {
        toggleHeading(this);
    };
    Editor.prototype.toggleBold = function() {
        toggleBold(this);
    };
    Editor.prototype.toggleItalic = function() {
        toggleItalic(this);
    };
    Editor.prototype.toggleBlockquote = function() {
        toggleBlockquote(this);
    };
    Editor.prototype.drawCode = function() {
        drawCode(this);
    };
    Editor.prototype.toggleUnOrderedList = function() {
        toggleUnOrderedList(this);
    };
    Editor.prototype.toggleOrderedList = function() {
        toggleOrderedList(this);
    };
    Editor.prototype.drawLink = function() {
        drawLink(this);
    };
    Editor.prototype.drawImage = function() {
        drawImage(this);
    };
    Editor.prototype.undo = function() {
        undo(this);
    };
    Editor.prototype.redo = function() {
        redo(this);
    };
    Editor.prototype.togglePreview = function() {
        togglePreview(this);
    };
    Editor.prototype.toggleFullScreen = function() {
        toggleFullScreen(this);
    };

    global.Editor = Editor;
})(this);